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Th<? Students' Quiz Scries. 

ANATOMY. 

A MANUAL FOR STUDENTS AND PRACTITIONERS, 
FEED JfBROCKWAY, M. D., 

Assistant Demonstrator of Anatomy, College of Physicians and Surgeons, New York, 
I AND 

iTb'MALLEY, M. D, 

Instructor in Surgery, New York Polyclinic. 



SERIES EDITED BY 

BERN B. GALLAUDET, M.D., 

Demonstrator of Anatomy, College of Physicians and Surgeons, New York; Visiting 
Surgeon Bellevue Hospital, New York. 




\> gQPYRI«/i r 



(NOV 18 1892 



PHILADELPHIA : 
LEA BROTHERS & CO. 






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. 



a* 



a 



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Entered according to Act of Congress, in the year 1892, by 

LEA BROTHERS & CO., 

In the Office of the Librarian of Congress, at Washington. All rights reserved. 



Westcott & Thomson, 
Sttreotypers and Eleotrotypers, Philuda, 



William J. Doknan, 
Printer, PhUada, 



PREFACE. 



The opportunity afforded by the preparation of this book for 
the presentation of a brief Modern Anatomy has been deemed too 
valuable to sacrifice by duplicating existing " Anatomical Com- 
pends." The science is steadily advancing in the discovery of 
new facts. Twenty years ago the German anatomists recorded dis- 
coveries which are only now coming to the notice of the American 
student. A hand-book can at most contain only the essentials of 
the science, and in the present instance the effort has been to 
select such knowledge as will be most useful to the student and 
the practitioner. 

In the hope of presenting some new descriptions not acces- 
sible to all students, I have compiled the sections on Osteology, 
Arthrology, and Myology from Henle and from Quain, while Gray's 
Anatomy and notes on the lectures of Prof. George S. Huntington 
of the College of Physicians and Surgeons, New York, have also 
been largely consulted. The order and classification of Henle 
have been followed throughout : joints are mostly from his work, 
and where his descriptions of them differ greatly from those of Eng- 
lish text-books, they have been described separately in fine print. 
Many muscular anomalies have been mentioned in fine print. 
New names for muscles as agreed upon by the German Ana- 
tomical Society have been marked "p. n." (proposed name). 
Illustrations from Gray, Quain, Henle, and Schwalbe have been 
reproduced to illustrate special points. English and metric meas- 
urements are both given, the English being approximately correct. 



IV PREFACE. 

Space has been gained by conciseness and by the omission of many 
monosyllabic words. It is to be noted that the questions are, in 
a sense, headings introducing generally a large amount of informa- 
tion in the answers. 

The Glossary has been written in the hope of promoting a cor- 
rect pronunciation of anatomical terms. 

I have to acknowledge the assistance of Dr. Andrew O'Malley 
and the Editor of the Series, who have written the sections on 
Angeiology, Neurology, and Splanchnology. In the latter section 
the relations of the viscera are with slight modifications those 
given by Professor George S. Huntington, and the works of Quain 
and Gray serve as the basis for the general descriptions of the 
viscera, as well as for the sections on Angeiology and Neur- 
ology. 

This volume is not intended to replace text-books, but will be 
found serviceable in facilitating the remembrance of knowledge 
gained from more extended works and at the dissecting-table. 

FEED J. BROCKWAY. 

105 W. 74th St., ) 
New York. J 



CONTENTS 



PAGE 

Definition and Subdivisions of Anatomy 17 

Embryology 17 

Descriptive Anatomy 19 



OSTEOLOGY. 

Bones of the Trunk : The Vertebral Column ; False Vertebrae ; 

Ossification of the Vertebrae ; The Thorax ; The Hyoid Bone . . 23 
Bones of the Head : Bones of the Cranium ; Bones of the Face ; 

The Skull as a Whole ; The Wormian Bones ; External Surface 

of the Skull ; Ossification of the Bones of the Head 35 

Bones of the Upper Extremity: The Shoulder; The Arm; The 

Forearm ; The Hand 64 

Bones of the Lower Extremity : The Pelvis ; The Thigh ; The 

Leg; The Foot 76 

AKTHKOLOGY. 

Henle's Classification of Joints 93 

Articulations of the Trunk and Head: Henle's Vertebral and 

Costal Ligaments 95 

Articulations of the Upper Extremity : The Shoulder-girdle 

and Joint; The Elbow and Forearm; The Wrist and Carpus; 

Accessory Ligaments of the Wrist 104 

Articulations of the Lower Extremity: The Pelvic Girdle; 

Ligaments between the Bones of the Trunk and Hip-bone; The 

5 



CONTENTS. 

PAGE 

Hip-joint; The Knee-joint; Ligaments between the Rones of 
the Leg; The Ankle-joint; Joints of the Foot; Henle's Classi- 
fication of the Ankle- and Foot-joints 120 



MYOLOGY. 

Muscles in General 138 

Muscles of the Trunk : Muscles and Fascia* of the Back ; Muscles 
and Fascia? of the Abdomen ; Lining Fascia? of the Abdomen ; 
Muscles and Fascia? of the Chest; Muscles and Fascia* of the 

Neck ; Muscles of the Head 139 

Muscles and Fascle of the Extremities: 173 

The Upper Extremity : The Shoulder; The Upper Arm ; The Fore- 
arm ; The Hand 173 

The Lower Extremity: The Hip and Thigh ; The Leg; The Foot . . 186 
Muscular Homologies 202 



ANGEIOLOGY. 

The Heart: Structure of the Heart 204 

Arteries: The Pulmonary Artery 208 

Systemic Arteries: Arch of the Aorta and its Brandies; Arteries 
of the Head, Neck, and Upper Extremity ; The Thoracic Aorta 
and its Branches; The Abdominal Aorta and its Branches; The 
Iliac Arteries and their Branches; Arteries of the Lower Ex- 
tremity and their Branches 208 

Veins : The Pulmonary Veins 233 

Systemic Veins: Superior Vena Cava and Innominate Veins; Veins 
of the Head and Neck; Veins of the Upper Extremity; Veins 
of the Trunk; Veins of Lower Extremity; Veins of the Pelvis; 

The Portal System * 233 

The Absorbent System 245 

NEUROLOGY. 

The Spinal Cord 249 

The Brain or Encephalon 252 



CONTENTS. / 

PAGE 

Cranial Nerves 266 

The Spinal Nerves 277 

The Sympathetic Nervous System 292 

Organs of Special Sense: The Eye; The Ear; The Nose;- The 

Tongue 297 



SPLANCHNOLOGY. 

Organs of Kespiration : The Larynx ; The Trachea ; The Thyroid 

and Thymus Glands ; Pleurae and Mediastinum; The Lungs. . 310 

The Organs of Digestion : The Mouth ; The Teeth ; The Palate ; 
The Tonsils; The Salivary Glands; The Pharynx ; The (Esopha- 
gus ; The Stomach ; The Small Intestine ; The Large Intestine ; 
The Liver; The Gall-bladder ; The Pancreas 318 

The Spleen and Suprarenal Capsules : The Spleen ; The Supra- 
renal Capsules 335 

The Urinary Organs and Peritoneum: The Kidneys; The 

Ureters; The Bladder; The Peritoneum 336 

Organs of Reproduction (Male) : The Prostate Gland ; The 

Penis ; The Male Urethra ; The Testes 342 

Organs of Reproduction (Female) 348 

External: The Vulva; The Vagina 348 

Internal : The Uterus ; The Fallopian Tubes ; The Ovaries ; The 

Parovarium 349 

The Mammary Glands 352 



ANATOMY. 



DEFINITION AND SUBDIVISIONS OF ANATOMY. 
What are the object and subdivisions of anatomy? 

Its object is to find out the structure of organized bodies. This sci- 
ence includes Human, Comparative, and Vegetable Anatomy. 

The animal possesses two tubes, the animal and vegetative : the former 
contains the spinal cord and brain, distinguishing in part the animal 
from the plant ; the vegetative tube is common to both, and encloses the 
organs of nutrition and reproduction. 

Human Anatomy is subdivided into Histology, or General Anatomy, 
and Descriptive, or Special Anatomy. The following pages treat of 
Descriptive Anatomy. 

EMBRYOLOGY. 
Briefly describe the process of development. 

The human ovum is a small cell, xt^} 1 mcn m diameter ; its wall is 
the vitelline membrane, its body the yolk, its nucleus the germinal vesicle, 
and its nucleolus the germinal spot. If all the food-yolk undergoes 
changes, as in mammals, the ovum is holoblastic ; if only part, as in 
fishes, it is meroblastic. When the ovum matures the germinal vesicle 
divides and extrudes two polar globules; inside the yolk is formed a 
female pronucleus. 

These changes occur whether the ovum is fecundated or not. Should 
another cell, the spermatozoon, enter the yolk, its tail disappears and its 
head becomes the male pronucleus. The union of the two pronuclei 
forms the first segmentation sphere. Halves are formed of this sphere, 
each one again splits, and so on : when about ninety-six cells are formed, 
an upper group of sixty-four will completely enclose a lower group of 
thirty-two. 

The outer group lines the vitelline membrane, and from it comes the 
primitive ectoderm, the epiblast or serous layer. From the enclosed 
group comes the primitive entoderm, the hypoblast or mucous layer; be- 
tween them is later developed the primitive mesoderm, the mesoblast or 
vascular layer. On the outer layer there appears a shaded patch, the 
area germinativa, and in this come in order (1) the primitive streak, (2) 
the medullary canal, (3) the chorda dorsalis or notochord, and (4) the 
2— A. '17 



18 ANATOMY. 

mesoblastic somites : the first is transient ; the third, round which the 
vertebral column forms, is more persistent ; the second and fourth are 
permanent. The primitive streak soon acquires a primitive groove. 

The medullary or neural canal is confined to the epiblast, and formed 
by two lateral ridges meeting dorsally. The chorda dorsalis is a thicken- 
ing of the hypoblast, and its remains are the centres of the interverte- 
bral disks. The lateral mesoblast cleaves into two plates : one clings to 
the epiblast, forming the somatopleure ; the other to the hypoblast, form- 
ing the spleinchnopleure. The former forms part of the wall of the 
body, the latter part of the wall of the alimentary tract, and between 
the two is the coelom, or pleuro-peritoneal cavity. 

In the paraxial mesoblast, in the region which afterward becomes the 
neck, is developed a linear series of quadrangular masses, the meso- 
blastic somites.^ 

At the anterior end of the neural groove are formed three primary 
cerebral vesicles ; later the anterior and posterior divide each into two, 
making five in all. 

The steps to be noted are — (1) formation of polar globules and the 
male and female pronuclei ; (2) segmentation of yolk ; (3) arrangement of 
cells inside the vitelline membrane into two groups ; (4) separation of 
cells into epiblast, mesoblast (two layers), and hypoblast; (5) formation 
of area germinativa; (6) primitive trace; (7) primitive groove caused 
by heaping up of "dorsal plates;" (8) neural canal formed by the 
meeting of dorsal plates; (9) under this canal formation of notochord 
from hypoblast; (10) a line of square segments, the mesoblastic plates; 
(11) somatopleure and splanchnopleure and body-cavity; (12) three 
primary cerebral vesicles; (13) curving of the embryo longitudinally and 
laterally, comparable to a canoe, the body-cavity corresponding to the 
well of the canoe; (14) the yolk-sac outside the body-cavity is the um- 
bilical vesicle, providing nutrition until the placenta is formed. 

What parts are derived from each blastodermic layer? 

From epiblast, the whole nervous system, brain, spinal cord, peripheral 
and sympathetic nerves ; epithelial structures of the organs of special 
sense ; epidermis and appendages, as hair and nails ; epithelium of glands 
which open upon the skin surface, as mammary, sweat, and sebaceous 
glands ; muscular fibres of sweat-glands ; epithelium of mouth, except 
that covering tongue, and of glands opening into it ; enamel of teeth ; 
epithelium of nasal passages and of glands and cavities opening into 
them. 

From mesoblast, genito-urinary organs, except epithelium of bladder 
and urethra; all voluntary and involuntary muscles, except muscular 
fibres of sweat-glands ; vascular and lymphatic systems ; serous mem- 
branes and spleen ; skeleton and all connective-tissue structures of body. 

From hypoblast, epithelium of alimentary canal from back of mouth 
to anus, and of glands which open into this part of the tube ; epithelium 
of Eustachian tube and tympanum ; epithelium of bronchial tubes and 



OSTEOLOG Y. 1 9 

air-sacs of lungs; epithelium of the vesicles of the thyroid; epithelial 
nests of the thymus ; epithelium of urinary bladder and urethra. 

DESCRIPTIVE ANATOMY. 
What are the systems of descriptive anatomy? 

I. Osteology, the bones; 2. Arthrology, the articulations ; 3. Myol- 
ogy, the voluntary muscles, fasciae, and aponeuroses ; 4. Angeiology, the 
heart, blood-vessels, and lymphatics; 5. Neurology, spinal cord, brain, 
nerves, and organs of the senses ; 6. Splanchnology, the organs of res- 
piration, digestion, reproduction, and urination. 

An organ is capable of isolation : organs make up a system, and sys- 
tems an apparatus. 

What are some of the descriptive terms ? 

The body is always supposed to stand erect, with hands at the sides 
and palms to the front. Superior and inferior correspond to cephalic 
and caudal, anterior and posterior to ventral and dorsal. As the body 
is bilaterally symmetrical, it may be divided into similar halves by a 
median plane passing from before backward. The line along which this 
plane meets the surface of the body is the median line. The words in- 
ternal and external refer to points nearer to or farther from the median 
plane. Henle uses median for internal, and lateral for external ; the 
former looks toward the median line, the latter from it. 

Sagittal denotes an antero-posterior direction in or parallel to the 
median plane ; coronal or frontal denotes a transverse direction at right 
angles to the sagittal. Other terms applied to surfaces or borders, like 
vertebral, sternal, radial, ulnar, flexor, extensor, proximal (nearest the 
trunk or centre), distal (away from the trunk), are often convenient. 

A surface is said to "look" in a certain direction when a perpendic- 
ular to the surface points in that direction. 

OSTEOLOGY. 

What is the skeleton ? 

The skeleton is the solid framework of the body, composed of bones 
completed \>y cartilage. In the lower animals there may be an endo- 
skeleton, the deeper framework corresponding to the human skeleton, 
and an exoskeleton, comprising the integument and hardened structures 
connected with it. All vertebrate animals possesses an endoskeleton ; 
some have an exoskeleton. Most invertebrate animals possess an exo- 
skeleton only. 

What are the uses of bones ? 

(1) They serve as levers upon which attached muscles act; (2) sup- 
port ; (3) protection of delicate organs ; (4) contribute to the formation 
of joints ; (5) by elasticity of curvature tend to diminish shocks. 



20 OSTEOLOGY. 

How are bones formed ? 

They are formed by ossification in three ways: (1) in cartilage, not 
from it; (2) in membrane; (3) subperiosteally. 

The bones of the vertex of the skull — i. e. the parietals, the frontal, 
the tabular part of the occipital, the squamous and tympanic parts of 
the temporal, the inner plate of the pter} T goid process, the bones of the 
face except the inferior turbinate and part of the lower jaw — are formed 
in membrane. The base of the skull and the other bones of the body 
are formed in cartilage. A deposit of bone begins at one spot, the 
primary cent re ; the shaft or diaphysis is formed from this. Most bones 
have other centres of ossification, secondary or tertiary, and parts de- 
rived from them are the epiphyses {growing upon). The growth of 
bone in length depends largely upon the cartilage between the epiphysis 
and diaphysis ; this cartilage acts as a buffer in concussions. The growth 
in circumference is by subperiosteal ossification. 

Some bones ossify early, according to their function — e. g. the lower 
jaw and ribs, because suction and respiration come into play at birth. 
The first primary centre to appear is in the clavicle, at the fifth week of 
foetal life ; the last secondary centre to appear is in the sternal end of 
the clavicle, at the eighteenth year. At birth nearly all primary centres 
have appeared (the pisiform not till the twelfth year), and only one 
secondary centre — viz. that for the lower extremity of the femur, pos- 
sibly one for the upper extremity of the tibia. 

What are the rules for the direction of medullary arteries ? 

1. The medullary arteries run from the knee and toward the elbow. 2. 
The secondary centre from which the artery runs is the first to appear. 
3. The epiphysis first to appear is last to unite (except in case of fibula, 
where its lower epiphysis appears first and unites first) . If there is but 
one secondary centre in a bone, the artery runs from it. Rule 1 may 
be remembered by flexing the knees and elbows, and noting that the 
medullary arteries run down as though impelled by gravity. 

The obliquity of the vascular canals is really due to the inequality of 
growth of the two ends : the one growing more rapidly carries the artery 
with it, 

Briefly describe the structure of bone. 

This description includes that of the periosteum, marrow, and bone 
proper. 

The periosteum, or bone-skin, consists of two layers, an outer fibrous 
and an inner vascular one, beneath which are granular cells called osteo- 
blasts. The periosteum serves as a nidus for vessels, and is related to 
the growth and renewal of bone. It is looser on young bone than on 
old, and looser on the shaft than on the extremities. The dura mater of 
the brain is allied to periosteum. 

The marrow fills the medullary canal, cancellous spaces, and large 



OSTEOLOGY. 21 

Haversian canals. The medullary canal is lined with endosteum. 

Marrow may be yellow or red: the former is in adult long bones 
and contains 96 per cent. fat. In the short and flat bones, in the 
cancellated ends of long bones, in the bodies of the vertebrae, in the 
cranial diploe, in the sternum and ribs, and in all bones of the foetus 
and infant, the marrow is red and fluid, containing 72 per cent, water 
and a trace of fat. Marrow may possess five kinds of cells : (1) fat- 
cells; (2) •marrow-cells proper, resembling white blood-cells, and possess- 
ing amoeboid movement; (3) small nucleated reddish cells; (4) cells 
containing one or two red blood-corpuscles ; (5) giant-cells (osteoclasts or 
myeloplaxes), which are concerned with bone-absorption. Marrow may 
help form and renovate blood, form bone, and has nutritive properties. 

Bone proper may be compact or cancellous ; the separate cancelli have 
the same structure as the compact bone. Long bones have an outer 
shell of compact substance, spongy tissue at the ends, with a dense layer 
beneath the articular cartilage, and a medullary canal. 

Flat bones have two compact plates enclosing a spongy layer, the 
diploe. 

Solid bone is made up of Haversian systems (Havers, an English ph} T - 
sician). A central hole is the Haversian canal, ■§%■$ inch in diameter, and 
five to fifteen concentric rings around it are the lamella?. Between the 
lamellae are dark specks, the lacuna 3 , which are connected with each other 
and the central canal by fine lines, the canaliculi. Lamellae may be con- 
centric, around Haversian canals; interstitial, between Haversian sys- 
tems; and circumferential, surrounding the bone. The canals connect 
the medullary cavity with the surface of the bone, allowing free permea- 
tion of blood-vessels. 

The lamellae may be stripped up as thin films, and seem bolted together 
by the perforating fibres of Sharper/. In thin plates of bone there are 
no Haversian canals, but lacunae and canaliculi are present. 

What is the arrangement of the vascular and nerve supply ? 

The arteries are periosteal, articular, and medullary (all are nutrient). 
The veins emerge from the bone in the same places that the arteries 
enter. Lymphatics accompany the vessels. Nerves enter with the arte- 
ries, and are destined for the vessels : none are known to end in bony 
tissue itself. 

What is the purpose of the medullary cavity? 

To allow greater surface for muscular attachment with economy of 
w r eight ; for strength, a hollow cylinder being stronger than a solid one 
of same weight, In some water animals the bones are nearly solid, act- 
ing as ballast. In birds the bones are light, with large medullary cavities 
filled with w r arm air from the lungs. In the human subject there are 
air-cells in a few bones. 



22 OSTEOLOGY. 

What are the physical and chemical characters of bone ? 

Bone consists one-third of animal matter, giving tenacity and elasticity, 
impregnated with earthy salts, two-thirds, in the form of minute gran- 
ules : this gives rigidity and brittleness. The analysis by Lehman is — 

Gelatin and blood-vessels, 33 per cent. 

Phosphate of calcium, 57 

Carbonate of calcium, 8 " . 

Fluoride of calcium, 1 " 

Phosphate of magnesium, ■ 1 " 

100 per cent. 

Some add 1 per cent, of oily matter. 

Pure bone is thought to be a definite compound, whether from a child 
or old person : it differs in compactness and arrangement. The petrous 
portion of the temporal, and the long bones as a whole, have an excess of 
inorganic matter compared with bones of the trunk — the upper extremity 
men; than the lower. In rickets the earthy matter may sink to 20 per 
cent,, instead of 66 per cent. Calcium phosphate forms more than half 
of bone and 88 per cent, of enamel of teeth. Bone is twice as strong 
as oak, three times as strong as elm, and twenty-two times as strong as 
freestone. A cubic inch will support 5000 pounds weight ; it requires 800 
or 900 pounds to fracture the femur. 

What is the number of bones in the human skeleton ? 
200 in the adult ; thus : 

bonS «»■ Total. 

f The vertebral column 26 . . 26 

Axial skeleton - 1 The sku11 • . . . 6 8 22 

Axial skeleton, . . . -j The hyoid bone x ± 

{ The ribs and sternum 1 12 25 

Appendicular skeleton, f Jhe upper limbs 32 64 

Fl ' I The lower limbs . . _ 31 62 

34 83 200 

The patella and pisiform are included, but not the ossicles of the ear or 
small sesamoid bones : the teeth belong to the epidermal layer. 

Into what classes are bones divisible? 

(1) Long or cylindrical, about 90 in number; (2) tabular or flat, for 
protection or muscular attachment, numbering 40 ; (3) short, for strength.. 
numbering 30; (4) irregular, mostly situated symmetrically across the 
median plane of the body, numbering 40. 

Mention some terms used in descriptions. 

There are eminences and depressions, an articular and non-articular 
subdivision, of each variety. 

Articular eminences are called heads and condyles ; non-articular emi- 



BONES OF THE TRUNK. 23 

nenecs are epicondyles, trochanters, tuberosities, tubercles, spines, lines, 
apophyses, etc. An apophysis [excrescence) has never been separate 
from the surface of bone: an epiphysis is developed from a separate 
centre. 

Certain adjectives used are — clinoid, like a bed ; coracoid, like a crow's 
beak: coronoid, the tip of a curve; hanmlar, like a hook; malleolar, 
like a mallet; mastoid, like a nipple; odontoid, like a tooth; pterygoid, 
like a wing ; spinous, thorn-like ; styloid, like a pen ; vaginal, ensheathinir. 

Articular cavities are cotyloid, like a deep cup ; glenoid, like a shallow 
cup; trochlear, pulley-like ; sigmoid, like the Greek letter for s. 

Non-articular cavities are fossce, sinuses, fissures, grooves, canals, hia- 
tuses, etc. 

BONES OF THE TRUNK. 

The clavicle and scapula do not belong to the trunk ; they form the 
shoulder girdle. 

The os innominatum goes to form the pelvic girdle, completed behind 
by the sacrum, which belongs to the trunk. The animal tube is enclosed 
by the vertebral column ; the vegetative tube is in front of this and be- 
hind the hyoid bone and sternum. The parts of the trunk are the ver- 
tebral column, the sternum and ribs, the hyoid, and bones of the skull. 

THE VERTEBRAL COLUMN. 

1. The rertehrrd column is composed of a series of vertebrae {verto, to 
turn), originally thirty-three in number. The upper twenty-four remain 
separate as movable or true vertebrae ; these are succeeded by five united 
into the sacrum ; then follow four dwindled segments united into the 
coccyx. These lower nine are the fixed or false vertebrae. 

Beginning at the skull, there are seven cervical, twelve dorsal or 
thoracic connected with ribs, five abdominal or lumbar, five sacral, and 
four coccygeal vertebrae. The number in the cervical region is constant; 
those between the dorsal and lumbar may vary reciprocally. If there 
are but eleven pairs of ribs, the twelfth dorsal vertebra will have lumbar 
characteristics; if thirteen pairs, the first lumbar will have dorsal cha- 
racteristics. A transitional Jumbo-sacral vertebra is met with, one side 
connected with the sacrum, the other having a free transverse process. 

Describe the characteristics of a vertebra. 

The first two cervical vertebrae are called rotation vertebrae : all the 
other true ones, flexion vertebrae. A representative vertebra, like the 
tenth dorsal, presents a body for the purpose of support, an arch and 
spinal foramen for protection, and seven processes for leverage. The body 
or centrum is a short cylinder ; the superior and inferior surfaces are flat, 
with a rim around the circumference. The front and sides are convex 
horizontally and concave from above down. The posterior surface is 



24 -BONKS OF THE TRUNK. 

slightly concave from side to side, and marked by one or two. venous 
foramina. The neural arch consists of two symmetrical portions meet- 
ing in the median plane behind. The anterior part or pedicle rises from 
a point on the body where the lateral and posterior surfaces meet ; the 
posterior part or lamina is broad and flat. The upper and lower borders 
of pedicles form vertebral notches, becoming intervertebral foramina 
between contiguous vertebrae. The spinous process projects back from 
the junction of the two laminae. The transverse processes, one on either 
side, project outward from the arch at the junction of the pedicle with 
the lamina. The articular processes, two superior and two inferior, 
project upward and downward at the point of origin of the transverse 
processes. 

The foramen is bounded anteriorly by the body, posteriorly and later- 
ally by the arch ; the series of rings thus formed constitutes the spinal 
canal. 

Describe a cervical vertebra. 

The body is small and broad transversely ; the upper surface is con- 
cave from the upward projection of lateral lips, and is sloped down in 
front. The under surface is rounded at the sides and lipped anteriorly, 
so there is interlocking at the sides to prevent lateral displacement — an 
anterior lip to prevent posterior, and articular processes to prevent 
anterior, dislocations. The laminae are long and flat. The superior and 
inferior notches are nearly equal in depth. The spinous processes are 
short and bifid. The transverse processes are directed outward, down- 
ward, and forward, and present at their extremities an anterior and 
a posterior tubercle. Each process is grooved above, and perforated 
vertically at its base by the vertebrarterial foramen for a vein, artery, and 
plexus of nerves. This foramen is between the two roots of the process, 
the posterior corresponding to a dorsal transverse process, and the 
anterior to a rib. The articular processes are placed at the extremities 
of a sh6rt vertical column of bone ; the superior articular surface looks 
back and up. The foramen is triangular, and larger than in any other 
region. The peculiar cervical vertebrae are the first, second, and 
seventh. 

Describe the atlas. 

The atlas (supporting globe of head) has no body or spinous process, 
but is a large ring with articular and transverse processes. The pos- 
terior part of the ring corresponds to the neural canal of the other ver- 
tebrae ; the anterior part is occupied by the odontoid process of the axis. 
The anterior boundary of the ring is the anterior arch, with a small 
tuberele in front for the longus colli muscle. Behind the tubercle is an 
articular surface for the odontoid. At the sides of the ring are the 
lateral masses bearing the superior and inferior articular processes^ All 
the articular processes of the atlas and the superior ones of the axis are 
in front of the vertebral notches. The superior articular surfaces of the 



THE VERTEBRAL COLUMN. 25 

atlas are oval and converge in front. They look up and in, and form a 
cup for the occipital condyles. They may be partially subdivided by a 
transverse groove, and below the inner margin of each is a tubercle for 

the transverse ligament. The inferior articular surfaces are slightly con- 
vex, nearly circular, and do not wholly cover or fit the superior"processes 
of the axis. The posterior arch presents in the median line either a 
ridge, hollow, or small tubercle. If a spinous process were well developed 
here, nodding of the head would be prevented. Just behind the lateral 
mass is a smooth sinus, the vertebral notch. The transverse processes 
are not bifid — are large and strong for attachment of rotatory muscles. 

Varieties. — The posterior or anterior bony arch may be incomplete; the an- 
terior root of the transverse process may be ligamentous. A spicule of bone 
may bridge over the superior vertebral notch, and the canal formed be sub- 
divided by other spicules. The artery and vein go through the upper subdi- 
vision, the suboccipital nerve through the lower. 

Describe the axis. 

The second vertebra, vertebra dentata or epistropheus (to "turn 
round "), forms an axis upon which the atlas carrying the head rotates. 
The body of the atlas is joined upon that of the axis in form of a tooth- 
like process, the odontoid. Its apex is pointed, and just below is an en- 
largement or head, both giving attachment to bands of the check liga- 
ment. 

The process has in front a smooth articular surface for the arch of the 
atlas, and behind a smooth groove for the transverse ligament. This 
makes a slight constriction, but hardly a neck. 

The anterior surface of the body presents a slight ridge separating two 
depressions. The superior articular surface lies close to the odontoid, 
upon the body in part and upon the pedicles ; they look up and out. 
The inferior articular surfaces are behind the upper, and resemble corre- 
sponding ones in the cervical region. The spinous process is grooved 
inferiorly — is very large and bifid, in contradistinction to that of the 
atlas. The transverse processes are short, with the anterior tubercle 
nearly suppressed. The inferior vertebral notch is in front of the artic- 
ular surface, which is the rule for both notches below this in the column. 

Describe the seventh cervical vertebra. 

This has a long spinous process, non-bifurcated, tending to slope down, 
and projecting under the skin ; hence the name vertebra prominens. The 
transverse processes are massive, slightly grooved, with a small foramen 
or none at all ; the posterior tubercle is large and the anterior one very 
small. The vertebral artery and vein do not pass through these for- 
amina : both veins may, sometimes the left artery does ; the vessels may 
enter no foramina till the fourth vertebra is reached. 

Varieties. — The spine of the sixth vertebra is not usually bifid ; in the negro 
this is the rule also for the third, fourth, and fifth. Bifurcation of spines is 
peculiar to the human skeleton. The anterior tubercle of the sixth is large, 



26 BONES OF THE TRUNK. 

and called Chassaignac's and carotid tubercle. The common carotid artery may 
be compressed against it: opposite this level the omo-hyoid crosses beneath 
the sterno-mastoid muscle; the, inferior thyroid artery crosses beneath the 
common carotid ; the cricoid cartilage is opposite, also the beginning of the tra- 
chea and oesophagus, the end of the larynx and pharynx. 

All known mammals have seven cervical vertebrae, except the sloth and 
manatee, which have six. There are two exceptions recorded in man. The 
number bears no relation to length of neck ; that of the whale and giraffe each 
contains seven. 

Describe the dorsal or thoracic vertebras. 

The body is relatively small, and heart-shaped ; its anteroposterior 
and transverse diameters are nearly equal, and its depth is greater behind 
than in front. Where the arch joins the body there are articular sur- 
faces for the heads of ribs, generally two on each side, one at the upper 
and one at the lower border. Between the neck of a rib and transverse 
process is the costo-transverse foramen. In the cervical region this is 
represented by the vertebral foramen, and in the lumbar region the space 
is filled by the bony mass of the transverse process. The cross-section 
of a dorsal body shows a slight median projection for purposes of strength, 
similar to the linea aspera of the femur. The laminae are broad and flat 
and overlap each other. 

The superior vertebral notches are shallow or absent ; the inferior are 
deep. 

The spinous processes are bayonet-shaped, and terminate in a slight 
tubercle. They are longest and most oblique from the fifth to the 
eighth. 

The transverse processes are directed out and back, and terminate in 
a clubbed extremity, which presents an articular surface for the tuber- 
osity of a rib, and also two indistinct^ tubercles, one from the upper and 
one from the lower border. The articular processes are nearly vertical, 
with their smooth surfaces (superior) looking back and out, the inferior 
in a reverse direction. 

The spinal foramen is nearly circular, and smaller than in other 
regions. 

What dorsal vertebrae present peculiar characters? 

The first, tenth, eleventh, and twelfth are to be distinguished. The 
first dorsal resembles the seventh cervical. Its body above is trans- 
versely concave and lipped. The superior vertebral notches are dee]), 
the superior articular processes are oblique, and the spinous process is 
nearly horizontal. On the side of the body, close to the upper border, 
is a whole facet for the first rib, and a very small demi-facet below for 
the second rib. 

The twelve ribs correspond to twelve joint surfaces, but these are di- 
vided, so that only the first, eleventh, and twelfth present single facets ; 
the first in addition has a half-facet, and the tenth has one demi-facet. 



THE VERTEBRAL COLUMN. 27 

The upper demi-facets become larger on succeeding vertebrae, and 
when the eleventh is reached it is a complete facet. 

The tenth dorsal touches only one rib on a side, and has a nearly com- 
plete facet, mostly on the pedicle at its upper border. The transverse 
process has a small facet. 

The eh venth dorsal has one complete facet on each side, but none on 
the transverse process. 

The twelfth dorsal has a single facet on each side. 

The inferior articular surfaces turn out, resembling the lumbar verte- 
brae. The spinous process is short and nearly horizontal. 

The transverse processes are short, and present near their extremities 
the external, superior, and inferior tubercles, which correspond respect- 
ively to the transverse, mammillary, and accessory processes of the lum- 
bar vertebrae. Rudiments of these tubercles may be seen on the tenth 
and eleventh vertebrae. The row of costal facets forms the anterior bor- 
der of the intervertebral foramina.^ The ribs in moving intrude some- 
what upon the vessels and nerves in those foramina; hence the "float- 
ing," most movable, ribs articulate with single vertebrae. 

The ninth dorsal may be lacking in the lower derai-facet ; the eleventh 
may take the lumbar type of articular process. 

Describe the lumbar vertebrae. 

These are the largest of the movable vertebrae. They have no costal 
articular surfaces, and no foramina through the transverse processes. 
The body is reniform in outline, broad transversely, and deeper in front 
than behind. The laminae are short and thick, the superior notches 
shallow, the spinous process horizontal, and broad and thickened at its 
extremity. 

The transverse processes are slender and project directly out ; they are 
in front of the articular processes, and are considered to be homologous 
with the ribs. Their extremities lie in series with the external tubercles 
of the lower dorsal transverse processes. The accessory process [anapoph- 
ysis) lies behind each lumbar transverse process at its base, and points 
down. It is large in some animals, and locks the vertebrae together. 

The articular surfaces are vertical, the superior concave looking back 
and in : the superior are farther apart than the inferior, and embrace an 
inferior pair above them. 

The mammilla ry process (metapopliysis) projects back from each su- 
perior articular process. The spinal foramen is triangular, larger than 
in the dorsal, and smaller than in the cervical regions. 

The fifth lumbar is massive, the inferior articular processes wider apart 
than the upper ; the transverse processes are broad and conical, and the 
laminae project into the spinal foramen. 

In the European the bodies of the lumbar vertebrae are collectively deeper 
in front than behind, but the individual segments vary. In the negro the 
depth of the five bodies is greater behind than in front. 



28 BONES OF THE TRUNK. 

FALSE VERTEBRA. 
Describe the sacral vertebrae. 

These in the adult form the os sacrum: it is placed between the two 
hip-bones, and with the coccyx completes the pelvic wall above and 
behind. The bone may be likened to a shovel in shape, and is wedge- 
shaped in four directions: (1) is narrower from side to side at its apex 
than at its base ; (2) is thinner antero-posteriorly at its apex than at its 
base ; (3) the dorsal surface is narrower than the anterior ; (4) a projec- 
tion into the articular surface of the ilium (Fig. 12). The bone presents 
anterior, posterior, and two lateral surfaces, a base, an apex, and a central 
canal for description. 

The ventral surface looks considerably downward, forming a projec- 
tion with the last lumbar, the sacro-vertebral angle of about 120°. This 
surface is concave from above down and from side to side, and is crossed 
by four horizontal ridges, indicating the union of five vertebrae. At the 
ends of the ridges are four anterior sacral foramina, which lead ex- 
ternally into grooves on the lateral masses. 

The two rows of foramina are vertical and parallel, not approaching 
below, as the width of the bodies are all equal. 

The dorsal surface, looks up and back, is convex and rough, and along 
the median line are three or four small spinous processes, more or less 
connected, forming a ridge. Below the ridge is a triangular opening, 
bounded by the imperfect laminae of the fourth and fifth sacral, and by 
the inferior articular processes of the last sacral, which are prolonged 
down into sacral cornier, meeting corresponding ones from the cocc}'x. 
On each side of the median ridge the united laminae are hollowed into 
the sacral groove, a continuation of the vertebral groove above ; next ex- 
ternally is a row of tubercles representing articular and mammillary pro- 
cesses ; next the four posterior sacral foramina, opposite to, but smaller 
than, the anterior. They correspond to the spaces between two transverse 
processes — the anterior to the spaces between two ribs. 

The lateral mass is that part external to the foramina, broad above 
and narrow below. It is made up of -broadened transverse processes, 
rudiments of which are seen outside the posterior sacral foramina: the 
first pair are large ; the second are smaller and enter into the formation 
of the sacro-iliac joint ; the third, fourth, and fifth give attachment to 
ligaments. Anteriorly are four shallow grooves, separated by ridges, 
which give attachment to slips of the pyriformis. Above and externally 
the lateral mass shows an uneven auricular surface with its convexity 
forward; it articulates with the ilium. Behind this the bone is still more 
rough for attachment of the posterior sacro-iliac ligament. The auric- 
ular surface rests on two and a half vertebrae, the larger part belonging 
to the first ; the upper three are therefore called the true sacral vertebrae, 
and the other two the caudal. Lower down the bone terminates in the 
inferior lateral angle, below which is a half-notch, forming a foramen 
with the coccyx for the fifth sacral nerve. 



FALSE VERTEBRJE. 29 

The base shows the reniform first sacral body, behind which is the 
triangular aperture of the sacral canal; on each side of this is a large ar- 
ticular process bearing a large mammillary process. In front of this is 
a vertebra] groove which helps form the last lumbar intervertebral fora- 
men. Externally is a modified transverse process, and in front of that 
a smooth triangular surface continuous with the iliac fossa, the ala of 
the sacrum. 

The apex is the body of the fifth sacral vertebra, transversely oval : 
it articulates with the coccyx. The sacral canal curves with the bone, 
and becomes smaller as it descends. A transverse section is triangular 
above, but flattened and then semicircular below. From it there pass 
out four pairs of intervertebral foramina, opening anteriorly and pos- 
teriorly into the anterior and posterior sacral foramina, and closed ex- 
ternally by the lateral masses. 

The human sacrum is characterized hy its great breadth compared to the 

t u on , • , /100 X breadth \ . ■ . _ . 

length. The sacral index 1 — I m the male European is 112, 

negro 106, gorilla 72. The sacrum may consist of six pieces, or rarely of four. 
The bodies of the first and second may not be united, forming a second 
"promontory " at this point. The sacrai canal may be open more than usual 
or open throughout. 

What are the differences in the sacrum of the male and female ? 
In the female it is wider, sacral index 116, is less curved, the upper 
half nearly straight, is more oblique, and forms a more marked prom- 
ontory than in the male. 

Describe the coccygeal vertebrse. 

These are very rudimentary, usually four in number, often five, 
rarely three. Of the first one the pedicles and superior articular cornua 
project upward, and help form the last intervertebral foramen. The 
short transverse process usually- bounds a notch for the anterior division 
of the fifth sacral nerve, or if it touches the inferior lateral angle of the 
sacrum, it forms a fifth anterior sacral foramen. 

The second vertebra has rudiments of transverse processes, and two 
small eminences in line with the cornua, representing the last traces of 
a neural arch. The third and fourth are mere nodules, and represent ver- 
tebral bodies only. In adult life the first piece is usually separate, and 
the other three united. All four may form one bone, which occurs 
oftener and earlier in the male. 

Steinbach observes that the male has most often five coccygeal vertebra?, 
and the female four or five with equal frequency. 

Describe the vertebral column as a whole. 

It is a central axis upon which other parts are arranged : above, it 
supports the head, laterally the ribs, and it restson the hip-bones below. 
Its average length measured along the curves is 28 inches in the male, 



30 BONES OF THE TRUNK. 

and 27 inches in the female ; persons seated in a row appear of about 
the same height. 

Viewed from the front, the column is formed of two pyramids applied 
base to base at the junction of the last lumbar with the sacrum. The 
upper pyramid can be divided into three — viz. the six lower cervical, with 
base at first dorsal ; the second is inverted, with the apex at fourth dor- 
sal ; and the third commences at the fourth dorsal and ends at the last 
lumbar. All three diameters of the vertebrae increase from the third 
cervical to the last lumbar : vertical diameter from §-l£ inches (14 mm. 
to 29 mm.), sagittal from f-lf inches (14 mm. to 35 mm.), transverse 
(does not increase in dorsal region) from |-2i inches (21 mm. to 55 mm.). 

The column presents a lateral curve convex to the right : this may be 
an indentation on the left side rather than a curve. Three theories are 
proposed: (1) liver draws right side over; (2) pulsating aorta pushes 
column over; (3) right-handedness. The last is most tenable. Viewed 
laterally, there are four curves, alternately convex and concave, the 
cervical, dorsal, lumbar, and pelvic; the first extends from the odon- 
toid to the second dorsal; the dorsal curve is concave forward and 
ends at the twelfth dorsal; the lumbar ends at the sacro-vertebral 
angle, and the pelvic ends at the tip of the coccyx. The dorsal and 
pelvic curves are primary, exist at birth, enter into the formation of 
bone-walled cavities, and are due to the conformation of the vertebral 
bodies. The dorsal is produced by pressure of viscera and weight of 
head and thorax. 

When the child begins to walk the ilio- psoas muscles pull the lumbar 
vertebrae forward, producing here and in the cervical region secondary or 
compensatory curves, mainly clue to the shape of the intervertebral disks. 
Hitting and the weight of the head also induce the cervical curve. 

The pathological curvatures are called kyphosis (humpbacked), scolio- 
sis (crooked, bent to one side), and lordosis (bent forward). 

Posteriorly, the sjnnes occupy the median line or may be normally 
twisted a little from it. In the cervical region they are short, horizontal, 
and bifid ; in the dorsal they are oblique above, vertical in the mid por- 
tion, and horizontal below ; in the lumbar they are horizontal. A cross- 
section of a cervical spine is semilunar ; of a dorsal, triangular ; of a 
lumbar, oblong. On either side of the spines is the vertebral groove, 
bounded externally in the cervical and dorsal region by the transverse 
processes, and in the lumbar by the mammillary processes. The trans- 
verse processes of the atlas are long ; of the axis, short, increasing to the 
first dorsal, thence diminishing to the last dorsal, and becoming suddenly 
much longer in the lumbar vertebras. In the cervical region the trans- 
verse processes are in front of articular processes and between interver- 
tebral foramina. In the dorsal region they are behind both. In the 
lumbar region they are in front of the articular processes and behind the 
intervertebral foramina. 

Intervertebral foramina are always in front of articular processes, ex- 
cept those of the atlas and the upper ones of the axis. They are named 



THE THORAX. 31 

{'nun the upper of the two vertebrae which go to form them, excepting 

in the cervical region, where there are eight, the fissure between the 
skull and atlas being called the first. 

In the cervical region the superior articular surfaces look back and up. 

In the dorsal region the superior articular surfaces look back and out. 

In the lumbar region the superior articular surfaces look back and in. 
The inferior surfaces have an opposite direction. 

The spinal canal has three sets of openings into it, the two rows of 
the intervertebral foramina and the intervertebral fissures between the 
laminae. It is narrowest in those parts having least motion — viz. in the 
dorsal and sacral regions. It is round and § inch (17 mm.) in diameter 
in the dorsal region ; is triangular with apex behind in the cervical and 
lumbar regions ; and largest of all in the cervical. 

OSSIFICATION OF THE VERTEBRA. 

Each vertebra is developed from three primary centres — one on each side for 
the lamina and processes, appearing at the sixth week of foetal life, and one for 
the body at the eighth week. Five secondary centres are added — three for the 
tips of the spinous and transverse processes, and two for thin annular plates on 
the circumferences of the upper and lower surfaces of the bodies. These are 
not united till the twenty-fifth year. A lumbar vertebra has two others for 
the mammillary processes. 

The atlas has three primary centres, the axis, six ; there are two lateral 
ones for the odontoid, between which a bit of cartilage remains till advanced 
life ; the apex of the odontoid has a separate centre. The seventh cervical 
usually has a separate centre in the anterior part of its transverse process, 
and likewise the first lumbar, though infrequently. The ossification of the 
laminse proceeds from above down, explaining the occurrence of spina bifida 
in the lower part of the column : ossification of the bodies appears first in the 
last dorsal and extends in both directions. 

The sacrum as a whole is developed from thirty-five centres — fifteen for bodies 
and arches, ten for epiphysial plates, three for the upper part of each lateral 
mass, and two for an auricular surface and thin edge below. The coccyx has 
four centres — one for each piece, sometimes two for the first one. 

THE THORAX. 

The skeleton of the thorax comprises the dorsal vertebrae, the ster- 
num, ribs, and costal cartilages. 

Describe the sternum. 

The breast-bone is an azygos bone in the median line at the front of 
the chest. It has attached the clavicles and seven upper costal carti- 
lages. It originally consisted of six segments, and is likened to a sword. 
The upper segment remains distinct as the manubrium or handle; the 
next four fuse into the body or gladiolus (little sword) ; the sixth por- 
tion is the ensiform or xiphoid j^'ocess (sword-like). 

The sternum is flattened from before backward, and curved with a 
slight convexity, to the front. It is. broad above, then narrow to the 
beginning of the gladiolus, then broad again, and narrow at the ensi- 



32 BONES OF THE TRUXT' 

form. The bone contains red marrow, confined in cancellous tissue be- 
tween two thin layers of compact bone. The manubrium (presternum) 
is the thickest part, concavo-convex on cross-section. Superiorly are 
three deep notches: the middle one is the semilunar or interclavicular 
notch ; the lateral ones look up back and out for articulation with the 
clavicles. Below the lateral notches on either side is a rough triangular 
surface for union with the first costal cartilage ; next is a sloping concave 
surface ; and at the lower angle a half notch for the second rib. The 
junction of the manubrium with the gladiolus is always prominent, and 
serves as a landmark for the second rib. 

The body (mesosternum) is marked anteriorly by three slight trans- 
verse ridges. Each lateral margin presents four notches and two half- 
notches: they approach each other from above down. The half-notch 
above is for the second cartilage ; the notches for the third, fourth, and 
fifth cartilages are opposite the lines of junction of the four segments ; 
the notch for the sixth cartilage and the half-notch for the seventh be- 
long to the inferior segment. So most of the cartilages of the true ribs 
articulate in front at junctions of segments, analogous to the connection 
of ribs with the vertebral column. 

The ens i form process (metasternum) projects down between the carti- 
lages of the seventh rib. It has various forms — may be bent forward, 
backward, or laterally, be forked or perforated, and is more or less carti- 
laginous. At its upper angle is a half-notch for the seventh cartilage. 
The sternum is subcutaneous in the median line, forming the floor of the 
sternal groove, with the supra- or episternal notch above and the infra- 
sternal depression at the ensiform process. 

The body of the male sternum is more than twice as long as the manu- 
brium; in the female it is less than twice the same length. The body at the 
junction of the third and fourth segments may be perforated by a sternal 
foramen, or rarely by a sternal fissure. Two small nodules, ossa suprastemalia, 
are sometimes found close inside the clavicular notches: they represent an 
episternal bone of lower animals, other remains of which are the interartic- 
ular nbro-cartilage of the sterno-clavicular joint. In flying birds a great keel 
exists along the middle of the sternum. In the male wild swan and guinea- 
fowl the sternum is tunnelled and contains the trachea. 

Describe the general characters of the ribs. 

The ribs (costae) are twelve in number on each side. ■ The first seven 
pairs, attached by costal cartilages to the sternum, are called sternal, 
true, or vertebrosternal ribs ; the remaining five pairs are asternal or 
false ribs : each of the upper three pairs of false ribs has its cartilage 
attached to the cartilage above it, vertcbro-cJiondral ; the last two pairs 
have no such attachment, and we floating or vertebral ribs. 

Each rib presents three parts — a body, an anterior and a posterior 
extremity. 

The posterior extremity is thickened into the head or capitulum: it 
has a superior and an inferior articular facet for articulation with two 



THE THORAX. 

vertebrae; the lower is the larger, and between them is a ridge for the 
interarticular cartilage. 

Next externally is the flattened neck, 1 inch long (eollum costae), and 
next the tuberosity, divided into two parts by an oblique groove. The 
inner and lower part is articular for the transverse process of the lower 
of the two vertebrae, with which the rib is connected; the outer and 
upper part is rough for the posterior costotransverse ligament. 

The body is laterally compressed, and over its most convex part is a 
rough line corresponding to the outer border of the sacro-lumbalis mus- 
cle, marking the angle; still farther forward is another line, the anterior 
angle. The inferior border presents the subcostal groove, best marked 
at the angle and disappearing in front ; it lodges intercostal vessels and 
nerves. Starting from the upper and inner border of the neck is a su- 
perior costal groove soon lost on the body. 

The anterior extremity is hollowed into a pit for union with the costal 
cartilage. The ribs are curved on three axes — a vertical one near the 
angle ; also a transverse one at this place, so that when the anterior part 
of the rib is horizontal the posterior will rise up ; and a longitudinal one, 
so that the anterior part looks up and the posterior part looks down. 
The upper ribs are nearly at right angles with the spine, and reach their 
greatest obliquity at the ninth. The seventh or eighth rib is the longest, 
after which they decrease to the twelfth. The first is broadest, and the 
twelfth narrowest. The distance from the angle to the tuberosity in- 
creases from above down. 

Describe the peculiar ribs. 

The first rib is not twisted, and its surfaces look nearly up and down. 
The head is small and has a single articular facet : the neck is slender, 
and the angle coincides with the tuberosity. On the upper surface is a 
rough impression for the scalenus medius muscle, and in front of that two 
smooth depressions with an intervening ridge : the posterior depression 
is for the '"third portion " of the subclavian artery, the ridge ending in 
the scalene tubercle (Lisfranc's tubercle) is for the attachment of the 
scalenus anticus muscle, and the anterior depression for the subclavian 
vein. There is no subcostal groove. 

The second rib is not twisted and has no angle (Henle) : it presents 
near the middle depressions for the scalenus posticus and serratus mag- 
nus muscles. It has a double articular facet. 

The eleventh and twelfth ribs have single articular facets, and only 
slight elevations to mark the tuberosities which do not articulate with 
the transverse process. 

The eleventh has a slight subcostal groove ; the twelfth has no angle. 

The number of ribs may be thirteen on one or both sides ; the gorilla and 
chimpanzee have each thirteen pairs of ribs. The added rib is most often 
connected with the first lumbar transverse process, sometimes with the 
seventh cervical vertebra, where it has a double attachment — viz. to the body 
and to the transverse process. The pleura descends to the same spot whether 

3— A. 



34 BOXES OF THE TRUNK. 

the twelfth rib be absent or not. The tenth rib may have but one articular 
facet. The twelfth rib varies in length from 8 inches to less than 1 inch. 

Describe the costal cartilages. 

They prolong the ribs to the sternum. Their breadth diminishes from 
the first to the last ; they become narrow toward their sternal extrem- 
ities ; their length increases to the seventh ; the first descends a little, 
the second is horizontal, the others, except the last two. ascend after 
following the direction of the rib for a short distance. Their external 
extremities are convex, and planted into the osseous tissue of correspond- 
ing ribs. The inner extremity of the first is united directly to the sternum 
without articular cavity ; the succeeding six have rounded extremities 
for the sternal notches. Each cartilage of the first three false ribs is 
united to the lower border of the one above it. The fifth, sixth, seventh, 
and eighth cartilages articulate with each other ; the eleventh and twelfth 
are pointed and unattached. 

The eighth may articulate with the sternum. The seventh may meet its 
fellow of the other side in frout of the ensiform. There may be no articula- 
tion between the fifth and sixth ; there may be one between the eighth and 
ninth. 

Describe the thorax as a whole. 

The bony thorax is conical, and flattened from before backward. The 
short antero-posterior diameter is characteristic of man, but in the lower 
mammals and human foetus it is longer than the transverse diameter. 
The posterior wall is convex forward, and a broad furrow on either side, 
the sulcus pulmonalis, is formed by the ribs as they project backward, so 
that the weight of the body is more equally distributed around the 
column. 

The anterior wall is convex and at an angle of 20°-25° with the pos- 
terior. 

A horizontal antero-posterior diameter from the base of the ensiform 
is 8 inches (20 cm. ) ; the transverse at the eighth or ninth rib is 11 inches 
(28 cm.) ; the vertical anteriorly is 6 inches (15.5 cm.), and posteriorly 
is 12 inches (31.5 cm.). The upper border of the sternum is opposite 
the lower edge of the second dorsal (Henle), and the lower border oppo- 
site the tenth dorsal. The sides slope out to the ninth rib. The upper 
aperture is contracted and reniform, and sloped downward ; the lower is 
irregular, and its margin ascends on each side from the tenth rib to the 
ensiform, forming the suhcostal angle. The intercostal spaces are wider 
above than below. 

The sternum is developed from six centres, one for each segment : the first 
to appear is at the sixth month in the manubrium ; the ensiform centre does 
not appear till the sixth year. The manubrium may have two or more 
centres, and the third, fourth, and fifth segments may have two centres, each 
placed laterally : if the bony parts formed from these do not meet, there is 
left the sternal foramen or fissure. The manubrium and body exception- 



BOXES OF THE HEAD. 



35 



ally join by bone, and usually remain separate till the twenty-fifth year. 
The ensiform unites in middle life. 

A single centre, situated posteriorly, appears for each rib at the eighth 
week ; after puberty two secondary centres appear in the cartilage of the head 
and tuberosity. The eleventh and twelfth ribs have none for the tuberosity. 

In the adult the first costal cartilage usually shows superficial ossification 
or even a complete bony sheath. In advanced life the other cartilages may 
be covered by bone, especially anteriorly : this tendency is stronger in the 
male. The cartilage itself is seldom ossified. 

THE HYOID BONE. 

Describe the hyoid bone. 

The hyoid, or os linguae, is situated at the base of the tongue opposite 
the second or third cervical vertebra, and is shaped like the Greek let- 
ter upsilon. Its body is compressed from above down ; the anterior sur- 
face looks up and forward, and is marked by a crucial ridge with a 
tubercle in the centre and depressions on either side for muscular at- 
tachment. Its posterior surface is concave and faces the epiglottis. 
The great cormia project back and are flat from above down. After 
middle life they have bony union with the body. The small cor una are 
short and conical, and project up and back from the junctions of the 
great cornua and body ; they give attachment to the stylo-hyoid liga- 
ments and have synovial articulations with the body. There are five 
centres of ossification for the five parts. 



BONES OF THE HEAD. 

The skull is divided into two parts, the cranium and face: the former 
protects the brain ; the face surrounds the mouth, nasal cavities, and 
orbits in part. 

Face has fourteen bones. 
(a) unpairing : 

Vomer, 



Cranium has eight bones. 
(a) unpairing : 

Occipital, 



{b) pairing: 



Sphenoid, 
Ethmoid, 
Frontal. 

Temporal, 

Parietal. 



{b) pairing 



Inferit 



:illa. 



Superior maxilla, 

Palate, 

Lachrymal, 

Inferior turbinate, 

Nasal, 

Malar. 



BONES OF THE CRANIUM. 
Describe the occipital bone. 

This bone (ob. caput, against the head) is flattened, lozenge-shaped, 
and bent on itself ; the upper anterior surface is concave, the posterior 



36 BONES OF THE HEAD. 

is convex. It articulates with six bones — two parietal, two temporal, the 
sphenoid and atlas. 

Below and in front the bone is pierced by the foramen magnum (for. 
occipitale) for the passage of the spinal cord and membranes, spinal por- 
tions of the spinal accessory nerves, and two vertebral arteries : the part 
behind the foramen is the tabular portion, in front is the basilar por- 
tion, at the sides are the condylar portions. 

The superior borders with the parietals form thelambdoid suture ; the 
inferior borders from the lateral angles to the jugular processes articulate 
with the mastoid, thence with the petrous portion of the temporal; the 
basilar unites with* the sphenoid by cartilage or by bone. The rhombic 
form may become eight-sided by secondary obtuse angles between the 
upper and lateral, the lateral and lower angles. 

The tabular portion presents posteriorly near the centre the external 
occipital protuberance, from which the superior curved line arches outward 
on each side to the lateral angles ; a little above this may usually be seen 
the highest or supreme curved line. Below the protuberance is a median 
external occipital crest, from the centre of which passes out the inferior 
curved line to the jugular processes. 

To the supreme curved line is the bony attachment of the epicranial apo- 
neurosis; to the superior curved line, most internally, the biventer cervicis, 
for the inner third the trapezius, next the occipitalis, sterno-cleido-mastoid, 
and splenitis capitis. Between the superior and inferior lines are internally a 
large impression for the complexus, and externally a small one for the supe- 
rior oblique. Below the lower line is an inner impression for the rect. cap. 
post, minor, and an outer one for the major. The ligamentum nucha? is at- 
tached to the protuberance and crest. 

The deep surface of the tabular portion shows two ridges crossing each 
other, one from the upper angle to the foramen magnum, one connect- 
ing the two lateral angles. Where these intersect is the interned occi- 
pital protuberance, not always opposite the external. The ridges mark 
off four hollows, the superior and inferior occipital fossa?, which lodge 
the posterior cerebral and the cerebellar lobes. The ridges are grooved 
for venous sinuses. The space where the longitudinal sinus is continued 
into a lateral one, generally the right, lodges the torcular Heropliili 
(wine-press of Herophilus). Below this the vertical ridge is sharp, and 
named the interned occipital crest. 

The condylar portions bear the articular surfaces for the atlas : these 
condyles converge _ toward the front, are doubly convex, and somewhat 
everted. At the inner side of each is a rough impression for a lateral 
odontoid ligament. Perforating the condyle from within out is the an- 
terior condylar foramen for the hypoglossal nerve and a branch of the 
ascending pharyngeal artery. Immediately above this foramen is a heap- 
ing up of bone designated as the eminentia innominata. Behind the 
condyle is ^posterior condylar fossa : it may )><■ perforated by a foramen 
for the passage of a vein from the lateral sinus; both fossa and foramen 
are inconstant. External to the condyle is the jugular process, analogue 



BONES OF THE CRANIUM. ^,7 

of a transverse process: it lies above the transverse process of the atlas, 
and it presents in front the jugular notch, which helps form the jugular 
foramen; the right notch is usually the larger. The extremity of the 
process presents an irregular facet for union with the temporal bone : this 
union is osseous at the twenty-fifth year. The upper surface presents the 
end of the lateral sulcus leading to the jugular notch : here the posterior 
condylar foramen opens if present. On the under surface is attached 
the rect. cap. lateralis muscle. 

The basilar process projects forward and upward in the middle of the 
base of the skull and at the top of the pharynx, increasing in thickness 
and diminishing in width. Superiorly is a basilar (/more for the medulla, 
and at either lateral margin a shallow sulcus for the inferior petrosal 
sinus. Interiorly in the middle line is the pharyngeal tubercle for 
aponeurotic attachment of the superior constrictor of the pharynx : on 
each side of it are attached the rect, cap. anticus major and minor 
muscles. 

The portion of bone above the superior curved line (intraparietal) is some- 
times separated from the rest by a transverse suture. The bone between the 
supreme and superior curved lines may be very prominent and constitute the 
torus occipitalis transversus (transverse bulge). An intrajugular process may 
project into the jugular notch. From the under aspect of the jugular process 
the paramastoid process may descend to the transverse process of the atlas. 
There is a rare articulation between the basilar process and anterior arch of 
the atlas or odontoid. Birds and reptiles have only a single occipital condyle, 
placed in front of the foramen magnum. The external occipital crest is 
greatly developed in most animals. 

Describe the parietal bone. 

This bone is quadrilateral, convex externally and concave internally, a 
little broader above than below. It articulates with five bones — the 
opposite parietal, the occipital, frontal, sphenoid, and temporal. Near 
the middle of the outer surface, nearer the lower than upper border, is 
the 'parietal eminence or boss. This is very prominent in young bones. 

Through or just below this are the superior and inferior temporal lines, 
f- inch apart: to the superior one is attached the temporal fascia, to the 
inferior the temporal muscle. The inferior line does not pass off the 
parietal upon the occipital bone ; below it is the temporal surface for 
origin of the temporal muscle. Near the upper border, and f inch (20 
mm.) from the posterior angle, is the parietal foramen for the exit of 
a vein, and usually entrance of a branch of the occipital artery. The 
sagittal suture between the two parietal foramina is inclined to oblite- 
ration. 

The deepest part of the inner surface opposite the parietal eminence 
is the parietal fossa. The inner surface is marked by furrows or canals 
for the meningeal vessels. A slight depression runs along the superior 
border, forming part of the sulcus for the longitudinal sinus. At the 
posterior inferior angle is a groove for the lateral sinus, which first runs 



38 BONES OF THE HEAD. 

across the occipital, then this angle of the parietal, then the mastoid por- 
tion of the temporal, and finally the jugular process of the occipital. 
Near the upper border of the bone are digital depressions for the lodg- 
ment of Pacchionian bodies (modified tufts of arachnoid membrane). 

The anterior border is alternately bevelled, so that the frontal rests 
upon it above and the parietal overlaps the frontal below, thus resisting 
the usual directions of violence. The inferior border is flattened and 
squamous, and divided into three parts, named from the bones over- 
lapping it, sphenoid, squamous, and mastoid from before backward. 

The parietal foramen may be absent on one or both sides or may be very 
large. This bone is bipartite iu some Australian skulls. 

Describe the frontal bone. 

The frontal (frons, forehead) arches up and back above the orbits, 
forming the fore part of the cranium. It articulates with twelve bones 
— the parietals and sphenoid, the malars, the nasals, superior maxillae, 
lachrymals, and ethmoid. Inferiorly are two thin horizontal laminae, 
the orbital plates, forming the roof of the orbits and separated by the 
ethmoidal notch. Three surfaces are presented for description. The 
anterior surface shows the greatest convexity on each side in the frontal 
eminence, separated by a slight depression below from the superciliary 
ridge, just above the orbit. In the middle line between the two ridges 
is a smooth surface, the glabella (without hair), also called nasal emi- 
nence. The orbital arch ends in extremities called the internal and 
external angular processes: the internal is slightly marked, and articu- 
lates with the lachrymal bone ; the external is prominent, and articulates 
with the malar. At the junction of the inner and middle third of the 
arch is the supraorbital notch or foramen for the supraorbital nerve and 
vessels. The temporal crest springs from the outer angular process, and 
is continuous with the inferior temporal line on the parietal. 

Inferior Surface. — The orbital plates are somewhat triangular, with 
their internal margins parallel. Close to the external angular process 
is the lachrymal fossa, and close to the inner process is the trochlear 
fossa for the pulley of the superior oblique. Between the internal an- 
gular processes is the nasal notch, and from its concavity the nasal 
process projects beneath the nasal bones and nasal processes of the 
superior maxillae and supports the bridge of the nose. On the posterior 
surface of this process are two grooves which enter into the roof of the 
nasal fossae; between the grooves is a median ridge, the nasal spine, 
which descends in the septum of the nose above the perpendicular plate 
of the ethmoid. Along the inner margins of the ethmoidal notch are 
irregular depressions forming the roof of cells in the ethmoid. Each 
border is marked inferiorly by two grooves, completing with the ethmoid 
the anterior and posterior internal orbital canals: the anterior transmits 
the nasal nerve from the orbit and anterior ethmoidal vessels ; the pos- 
terior transmits the posterior ethmoidal vessels. The frontal sinus opens 



BONES OF THE CRANIUM. 39 

at the root of the nasal process. It is between the outer and inner 
tables, over the root of the nose and divided by a bony septum. Out- 
side and behind the orbital surface is a rough triangular area for articu- 
lation with the great wing of the sphenoid. 

Ctrchml Surface. — This forms a large concavity for the anterior lobes 
of the cerebrum. The orbital plates are convex and marked by ridges 
and depressions, and are so thin as to be transparent: these plates make 
an angle of about 60° with the upper part of the bone. From the upper 
margin descends the frontal sulcus, running into the frontal crest at the 
lower margin. At the base of the crest is usually a groove converted 
into the foramen cceeum by the approximation of the ethmoid; this is 
usually open in children, but blind in adults. The sides of this surface 
present grooves for the meningeal vessels. The thin transverse edge 
bounding the surface behind articulates with the greater and lesser wings 
of the sphenoid. 

The trochlear fossa may be absent or have in addition a trochlear spine. 
The bone may be divided by the frontal or metopic suture, the infantile 
halves having failed to unite : this occurs in 8 per cent, of European skulls, 
5 per cent, of Mongolian, and 1 per cent, of African. A trace of the suture 
is seen in nearly all adult frontal bones just above the nasal notch. 

Describe the temporal bone. 

The temporal bone {tempus, time, as hair first becomes gray in this 
region, indicating age) helps form the side and base of the skull and eon- 
tains the organ of hearing. It presents four parts — the squamous, mas- 
toid, and pyramidal, which includes the petrous and tympanic. It ar- 
ticulates with five bones — posteriorly and internally with the occipital, 
above with the parietal, in front with the sphenoid and malar, and below 
w 7 ith the inferior maxilla. 

The squamous portion (scale), or squamo-zygomatie, presents a 
vertical portion and a narrow horizontal portion at the base of the skull. 
It is limited above by an arched border describing^ two-thirds of a circle. 
The outer surface is vertical, with a slight convexity, and forms part of 
the temporal fossa. This portion overlaps the mastoid. Above the 
aperture of the ear is a vertical groove for the middle temporal artery. 

The zygoma is connected with the lower and outer part of the squa- 
mous portion : it is broad at its base, with surfaces looking up and down ; 
it then twists on itself, so that it has inner and outer surfaces, upper and 
lower borders. The upper border is thin and longer than the inferior, 
which is short and arched ; the anterior extremity articulates with the 
malar. The zygoma is attached by two roots : the anterior, continuous 
with the lower border, is a broad convex ridge directed inward, called 
the eminentia articularis. At the junction of this with the zygoma is a 
tubercle for the external lateral ligament of the lower jaw. The poste- 
rior root prolongs the upper border of the zygoma as the supramastoid 
crest, which becomes continuous with the lower temporal line ; it is above 
the suture between the squama and mastoid. Between the two roots is 



40 BONES OF THE HEAD. 

the glenoid fossa : its articular portion is bounded behind by the post- 
glenoid process^ sometimes called the middle root of* the zygoma. It is 
strongly developed in some mammals to prevent posterior dislocation of 
the lower jaw. The inferior aspect of the horizontal portion presents 
three districts — the auricular, articular, and zygomatic, from behind 
forward. The auricular part forms the upper concave margin of the 
external auditory meatus and a part of the roof of the external ear. 
The next portion is the glenoid fossa, which is divided into two parts by 
the transverse fissure of Glaser. The posterior part is non-articular, 
formed by the tympanic plate and lodging part of the parotid gland. 
The anterior part of the fossa is articular, bounded behind by the post- 
glenoid process and in front by the eminentia articularis ; it is the fossa 
mandibular is, concavo-convex for the condyle of the lower jaw. The 
fissure of Glaser is a double cleft. The first fissure behind the artic- 
ular fossa is the petro-squamous (fps, Fig. 1), next comes a narrow pro- 
jection of the tec/mm tympani (tt / ) from the petrous, and next the 
petro-tympanic fissure or Glaserian fissure proper : it lodges the slender 
process of the malleus and tympanic branch of the internal maxillary 
artery. Farther in, and external to the Eustachian tube, is the canal of 
Huguier, by which the chorda tympani nerve enters. The outer part 
of the Glaserian fissure is entirely closed. 

Sometimes a " false jugular foramen " is present in the squamous, by which, 
in the embryo and many animals, blood flows from the cranium to the exter- 
nal jugular vein. It is between the articular fossa and external auditory 
meatus. 

In front of the articular eminence, and separated by a slight ridge 
from the temporal surface, is a small triangular infratemporal surface, 
entering into the zygomatic fossa. 

The inner surface of the squamous is concave and presents cerebral 
impressions and meningeal grooves. A narrow horizontal part helps 
form the anterior wall of the tympanum. 

The supenor border is thin and fluted, and overlaps the parietal bone. 
The parietal notch marks the junction of the superior border with the 
mastoid : the squamo-mastoid suture passes from this notch to the poste- 
rior edge of the external auditory meatus. 

The antero-inferior border is thick, and bevelled above continuously 
with the upper border at the expense of the inner surface, below at the 
expense of the outer — all for articulation with the great wing of the 
sphenoid. 

The mastoid portion (teat-like) is rough for muscular attachment, 
and prolonged down behind the auditory meatus as the mastoid jwocess. 
At the posterior border is the mastoid foramen, sometimes foramina, trans- 
mitting veins from the lateral sinus and a mastoid artery from the occip- 
ital : the foramen is inconstant, and may be in the occipital bone or in 
the masto-occipital suture. On the inner side of the mastoid process is 
the digastric fossa for attachment of the posterior belly of the digastric, 



BONES OF TIIK CRANIUM. 



II 



and internal to this is the sulcus occipitalis for lodgment of the occipital 

artery. 
The internal surface shows the fossa sigmoidea^ which is a part of the 

snleus for the lateral sinus: the mastoid foramen opens into it. A sec- 
tion of the mastoid portion shows a number of communicating cells ; be- 
low in the mastoid process they are developed after puberty and are 
arranged vertically. Above these is the antrum mastoideum^ which is a 
horizontal cellular cavity, a part of the middle ear: its roof and postero- 
lateral wall is formed from the petrous portion, and is continuous with 
the roof and side of the tympanum. Its anteromedian wall belongs to 
the mastoid. Below it connects with the mastoid cells : its opening into 
the tympanum is large and on a level with the foramen ovale, so the floor of 
the tympanum passes in front into the Eustachian tube and behind into 
the mastoid antrum. The superior border of the mastoid is rough, slopes 
back, and articulates with the postero-inferior angle of the parietal : the 
posterior border articulates with the occipital between its lateral angle 
and jugular process. 

The pyramidal portion includes the petrous (stone) and tympanic 
(drum). The petrous portion is a four-sided pyramid with its base turned 
out, and its long axis inward, forward, and slightly downward. The 
axes of the two portions if prolonged would meet at the posterior edge 
of the nasal septum. This portion presents four borders — superior, 
inferior, anterior, and p)osterior ; and four surfaces — antero-internal 



FTC4. 1. 




(iA, Fig. 1), postero-internal (ip), antero-external (ea), and postero-ex- 
ternal (ep) ; also a base and an apex. The base is concealed in its 
upper half by the squamous and mastoid, and covered below, where these 
diverge, by the tympanic portion. The apex is received into the angle 
between the great wing of the sphenoid and the basilar process, and pre- 



42 BONES OF THE HEAD. 

sents tlif anterior orifice of the carotid canal, and forms the postero-ex- 
ternal boundary of the foramen lacerum. 

The antero-internal surface is in the middle fossa of the skull, and 
separated from the squamous portion by the fissura petro-squamosa 
(pps). This surface presents a little behind its centre the eminentia 
arcuata, covering the superior semicircular canal ; in front of this is a 
groove leading to the hiatus Fallopii, which leads to the aqueduct of 
Fallopius ; it transmits the large superficial petrosal nerve and the pe- 
trosal branch of the middle meningeal artery. Outside this is a groove 
and small foramen for the small superficial petrosal nerve. Near the 
apex the wall of the carotid canal is deficient ; above this is a shallow 
depression for the Gasserian ganglion. Between the petro-squamous 
fissure externally and the hiatus Fallopii and eminence of the superior 
semicircular canal internally is a thin lamina which roofs in the tym- 
panum and a common canai for the Eustachian tube and tensor tympani 
muscle : it is the tegmen tympani, tt', a process of the petrous. 

The postero-internal surface is in the posterior fossa of the skull, and 
continuous with the inner surface of the mastoid. Near the centre, but 

nearer the upper than the lower bor- 
Fig. 2. der, is a large orifice, the porics acust. 

aofrll. fln.cRiB.sup. int., leading into a canal \ inch (6 mm. ) 

long, which is the internal auditory 
meatus; this is terminated by the Jam- 
eniSTKFnLC,£L -t^^M^ nRCmBMEO ina cribrosa (Fig. 2). A transverse 
roM.c£MT.mcH^^^^M~ ridge, crista faJciformis, separates a 

^&&^ fob. sing small superior from a large inferior 

jmerspi/froffffM. fossa. A faint perpendicular crest di- 

vides these into four fossae. The facial 
nerve enters the aqueduct of Fallopius in the upper anterior fossa ; the 
area cribrosa superior is the perforated part of the upper posterior fossa 
for auditory nerves going to the utricle, superior, and external auditory 
canals ; below this is the area cribrosa media, conveying an auditory 
branch to the saccule ; also the foramen singulare for a branch to the 
posterior auditory canal ; in the lower anterior fossa is the tractus spiralis 
foraminulentus, for the cochlear division of the auditory nerve, ending 
at the foramen cent rale cochlea:. 

Behind the auditory meatus is a small slit, the opening of the aque- 
duct of the vestibule, transmitting a small artery and vein and lodging a 
process of dura mater which encloses the saccus endolymphaticus ; above 
and between these is a depression or fissure, the subarcuate fossa, which 
extends into the arch of the superior semicircular canal and represents 
the floccular fossa of animals. 

The postero-external surface forms part of the base of the skull. 
Beginning at the apex, is first a quadrilateral surface for the origin of 
the levator palati and tensor tympani muscles, the lower aperture of the 
carotid canal, which is first vertical and then horizontal ; vertically be- 




BONES OF THE CRANIUM. 4.S 

Death the internal auditory meatus is the three-sided opening of the 
aqueduct of the cochlea, which in early life transmits a vein ; next be- 
hind is the jugular fossa, which forms the jugular foramen when oppo- 
site the jugular notch of the occipital. 

In front of the bony ridge, between the carotid canal and jugular 
fossa, is a small foramen for Jacobsoris nerve (from the glosso-pharyn- 
geal) to the tympanic plexus ; this foramen usually splits to give exit to 
the small deep petrosal icarotico-tyrnpanicus superior) from the tym- 
panic to the carotid plexus. Externally in the ascending part of the 
carotid canal is a small foramen for the carotico-tympa nicus inferior, a 
sympathetic nerve going from the carotid plexus to the tympanic. On 
the outside of the jugular fossa is a foramen for Arnolds nerve from the 
pneumogastric : its canal runs through the petrous transversely and out. 
and splits into two, an inner to meet the facial canal, £ inch (5 to 6 mm.) 
above the stylo-mastoid foramen, and the other to open at the tympano- 
mastoid (auricular) fissure. 

Behind the jugular fossa is the jugular facet, for articulation by syn- 
chondrosis with the jugular process of the occipital. Externally is the 
styloid process, enclosed between the layers of the vaginal process. It 
gives attachment to three muscles and two ligaments. Between the sty- 
loid and mastoid processes is the stylo-mastoid foramen, the end of the 
aqueductus Fallopii, which passes first out and back over the labyrinth, 
then in and back, and then down to terminate here : the stylo-mastoid 
artery enters this foramen. 

The an tero-externcd surface is free anteriorly for a short distance, and 
articulates with the great w T ing of the sphenoid ; posteriorly it is con- 
cealed by the tympanic plate (pt, Fig. 1). 

At the angle between the squamous and petrous portions is the open- 
ing of a canal the musculo-tubarius (cm), incompletely divided into two 
by a projecting lamella, the cochleariform process or septum tubas (sttj). 
The upper groove is for the tensor tympani muscle, and the lower is the 
bony wall of the Eustachian tube. This common canal is covered by 
the tegmen, its inner wall is the antero-external surface of the petrous, 
and its floor and outer wall are the tympanic plate. The septum tubce 
rarely reaches the opposite wall, and rises from the anterior wall of the 
carotid canal (cca), This wall is made of two thin lamellae with diploe 
between, in which runs the small deep petrosal nerve. The superior 
border is grooved for the superior petrosal sinus, and gives attachment 
to the tentorium cerebelli. The posterior border presents on its inner 
portion a half groove for the inferior petrosal sinus, and externally the 
margin of the jugular fossa. From the apex, where a bony projection 
often overhangs the inferior petrosal groove, a fibrous band, the petro- 
sphenoidal ligament, extends to the side of the dorsum sellae, and com- 
pletes a foramen for the inferior petrosal sinus and sixth nerve. The 
anterior border has two parts — an outer, forming the petro-squamous 
fissure, and an inner free portion to form the petro-sphenoidal suture. 
The inferior border is largely concealed by the tympanic and petrous 



44 BONES OF THE HEAD. 

portions: near the apex it is indistinct, and here the bone is rather 
three-sided. 

The tympanic portion is beneath the petrous and between the mas- 
toid and squamous. At birth it is a ring from which is developed the tym- 
panie plate. The thickened outer extremity of this plate is the external 
auditory process, a curved, uneven lamina forming the anterior and in- 
ferior wall of the external auditory meatus and tympanum. The upper 
margin of the plate is concealed by the petrous and forms the posterior 
boundary of the fissure of Glaser. Its lower margin descends as a sharp 
edge, the vaginal jyrocess : it is continuous with the inferior border of 
the petrous portion. 

Describe the sphenoid. 

The sphenoid bone (wedge-like) is placed across the base of the skull 
near its middle, and binds the other cranial bones together. It helps 
form the cavities of the cranium, orbits, and nasal fossae, and has to do 
with six pairs of cranial nerves. It resembles a bat with outstretched 
wings, and consists of a body, greater and lesser wings, and pterygoid 
processes. It articulates with twelve bones, all those of the cranium, and 
five of the face; posteriorly with the occipital and temporals, anteriorly 
with the ethmoid, palatals, frontal, and malars, laterally with the tem- 
porals, frontal, and parietals, interiorly with the vomer and palatals, and 
sometimes with the superior maxillae. 

The body is hollowed into two cavities separated by the sphenoidal 
septum, and opening anteriorly into the upper and back part of the 
nasal fossae behind the superior turbinate bone. 

The superior surface presents in front the ethmoidal spine, articulating 
with the cribriform plate of the ethmoid. On either side of this surface 
is a slight depression for the olfactory lobe, and its posterior margin is 
the limbus sphenoidalis. Behind this, on a lower plane, is the optic 
groove, terminating on either side in the optic foramen. Next is the 
olivary eminence (tuberculum sellce), and next the pituitary fossa, or sella 
Turcica (Turkish saddle): it is occasionally bounded in front by two 
middle cl in o id processes ; behind is a square lamina, the dorsum sellce or 
dorsum ephippii (back of saddle), which slopes posteriorly down and 
back into the basilar groove: this slope is the clivus Blumenbachii (Blu- 
menbach's hill). 

The upper angles of this lamella project over the fossa as the posterior 
clinoid processes; the sides are grooved, for the sixth pair of nerves. 
The sides of the body present a winding groove curved like the letter./* 
for the carotid artery in the cavernous sinus. Behind its commence- 
ment, at the lower lateral angle of the dorsum sella}, is the petrosal pro- 
cess of the sphenoid, to fit against the apex of the petrous ; opposite 
this, on the other side of the groove, is a tongue-like process, the lingula 
sphenoidalis. 

The posterior surface is quadrilateral, and united to the basilar process 
by cartilage in early life, and by bone after the twenty-fifth year. 



HONKS OF THE CRANIUM; 15 

The anterior surface is marked in the middle line by the sphenoidal 
crest : which articulates with the perpendicular plate of the ethmoid. 

On each side of the crest is a mesial and lateral part : the lateral shows 
half-cells, to be completed by the ethmoid and orbital plate of the pala- 
tal ; the mesial part is smooth, and gives entrance anteriorly into the 
sphenoidal sinus, and forms part of the roof of the nose. 

The inferior surface presents the rostrum (beak), which continues the 
sphenoidal crest and fits between the alse of the vomer. 

The sphenoidal turbinate bones (sponyy bones, concJue sphenoidale*, bones of 
Bertin) form a considerable part of the anterior wall of the body of the 
sphenoid. They are curved and triangular, with apex backward. A small 
portion of them sometimes appears on the inner wall of the orbit between 
the ethmoid, frontal, sphenoid, and palate bones. 

Each lateral surface of the body is mostly occupied by the attachment 
of the greater wrings, except in front a free surface bounds the sphenoidal 
fissure and forms the hindermost part of the inner wall of the orbit. 

The small or orbital wings (processes of Ingrassias) extend horizon- 
tally outward on a level w r ith the fore part of the superior surface of the 
body : the extremity of each is pointed and comes almost into contact 
with the great wing. The inferior surface forms the upper boundary of 
the sphenoidal fissure and part of the roof of the orbit. The anterior 
border articulates with the orbital plate of the frontal ; the posterior is 
free, and forms the boundary between the anterior and middle fossae of 
the skull, and terminates internally in the anterior clinoid process. Be- 
tween this clinoid process and the olivary eminence is a semicircular notch 
in which the carotid groove ends. The optic foramen perforates the 
base of the wing, the parts above and below being called its roots. 

The great or temporal icings project out and up from the sides of the 
body : the back part of each is horizontal and fills the angle between the 
squamous and petrous portions of the temporal ; from its extremity pro- 
jects downward the spinous process. The fore part is vertical and three- 
sided, and lies between the cranial cavity, the orbit, and temporal fossa. 

The cerebral surface is concave, and forms part of the middle fossa of 
the skull. 

The external surface (temporozygomatic) is divided by the infratem- 
poral crest into a lower part looking down into the zygomatic fossa, and 
an upper part looking out into the temporal fossa. 

The anterior surface looks forward and inward, and consists of the 
orbital plate for the external wall of the orbit, and of a smaller portion 
above the pterygoid process which looks into the spheno-maxillary fossa 
and is perforated by the foramen rotundum. 

The posterior border near the body bounds the foramen lacerum, and 
in its lateral part articulates with the petrous, forming a groove beneath 
for the cartilaginous portion of the Eustachian tube. The external bor- 
der, commencing at the spinous process, articulates w r ith the squamous, 
and above it overlaps the anterior inferior angle of the parietal bone. 



16 BOXES OF THE HEAD. 

In front of this is a triangular surface formed by the upper margins of 
the cerebral, orbital, and temporal surfaces. The anterior margin artic- 
ulates above with the malar : below this is a free horizontal edge separat- 
ing the zygomatic from the spheno-maxillary surface. Above and inter- 
nally the orbital and cerebral surfaces meet at a sharp border which 
forms the inferior boundary of the sphenoidal fissure, and often shows a 
bony projection for the lower head of the external rectus. 

The •pterygoid (wing-like) processes project downward and forward, 
angle of 110° to 115°, from the junction of the body and great wings. 
Some consider them to rise from two roots, one representing a transverse 
process, one a rib, and the Vidian canal, the costotransverse foramen. 
Each consists of two plates united in front and diverging behind, form- 
ing the pterygoid fossa for the origin of the internal pterygoid muscle. 
The external plate is broad and extends out and back, and gives origin 
by its outer surface to the external pterygoid muscle. The internal plate 
is long and narrow, and prolonged below into the ha inula r (hook-like) 
process, round which plays the tendon of the tensor palati muscle. The 
upper part of the inner plate turns in beneath the body, and remains 
distinct as a slightly raised edge, the vaginal process, which meets the 
everted margin of the vomer. At the angle of the vaginal process with 
the internal plate is a groove which, with the sphenoidal process of the 
palate, forms the pterygopalatine canal. Posteriorly, at the base of 
the inner plate, is the pterygoid tubercle, to the inner side of and below 
the Vidian canal : between this and the pterygoid fossa is the scaphoid 
fossa for the origin of the tensor palati muscle. Lower down, on the 
posterior margin of the plate, is the processus tubarius, which supports 
the cartilage of the Eustachian tube. Between the lower ends of the 
plates is the pterygoid notch, occupied by the pyramidal process of the 
palate bone. 

Name the fissures and foramina of the sphenoid. 

Each half presents a fissure, four foramina, and a canal. The sphe- 
noidal fissure is the oblique interval between the great and small wings, 
closed externally by the frontal bone. It opens into the orbit and trans- 
mits the third, fourth, ophthalmic division of the fifth, and the sixth cra- 
nial nerves, some sympathetic filaments from the cavernous plexus, the 
orbital branch of the middle meningeal artery, recurrent branch of the 
lachrymal artery, and the ophthalmic vein. Above and to the inside of 
this fissure is the optic foramen, piercing the base of the small wing and 
transmitting the optic nerve and ophthalmic artery. The foramen 
rjotundum pierces the great wing below the sphenoidal fissure and trans- 
mits the superior maxillary nerve. Behind and external to this is the 
foramen ovale, near the posterior margin of the great wing, sometimes 
incomplete: it transmits the inferior maxillary nerve, the small menin- 
geal artery, and sometimes the small superficial petrosal nerve. The 
foramen spinosum pierces the great wing near the posterior angle, and 
transmits the middle meningeal artery and n. spinosus, a recurrent branch 



BONES OF THE CRANIUM. 47 

of tho inframaxillary. From the foramen spinosum projects backward a 
thin horizontal spheno-petrosal lam inn. which reaches the upper border 
of the Eustachian canal on the petrous. 

The Vidian canal pierces the base of the internal pterygoid plate 
antero-posteriorly ; it passes from the foramen lacerum to the spheno- 
maxillary fossa, transmitting the Vidian nerve and vessels. 

A spicule of bone may connect the middle clinoid process (when present) 
with the anterior, forming a carotico-clinoid foramen for the carotid artery. 
Interclinoid ligaments are normally present beneath the dura. The outer 
pterygoid plate may be connected by bone or ligament with the spinous 
process. The foramen of Vesalius for an emissary vein is sometimes present 
on the inner side of the foramen ovale. The canaliculus innomimatus is some- 
times present for the small superficial petrosal nerve internal to the foramen 
spinosum. 

Describe the ethmoid bone. 

The ethmoid (sieve-like) projects down between the orbital plates of 
the frontal, and enters into the formation of the cranium, orbits, and 
nasal fossce. It consists of thin plates enclosing irregular cells — a ver- 
t iced plate and two lateral masses united above by the horizontal cribri- 
form plate. 

It articulates with thirteen bones — fifteen including the sphenoidal 
turbinate — the frontal, sphenoid, and vomer, the nasals, lachrymals, 
superior maxillse. palatals, and inferior turbinate bones. The vertical 
plate forms the upper third of the nasal septum, and presents grooves 
and canals for olfactory nerves. Its superior border appears in the 
cranial cavity as the crista galli (cock's comb) ; posteriorly this process 
is thin, and anteriorly is broadened into two alar processes, between 
which is usually a groove completing the foramen caecum with the 
frontal. If the vertical plate be deflected below the cribriform, the 
crista galli is inclined in the opposite direction. The anterior border of 
the plate articulates with the nasal spine of the frontal and with the 
nasal bones ; the inferior border in front with the triangular cartilage of 
the nose, and behind with the vomer; the posterior margin with the 
sphenoidal crest. 

Each lateral mass or labyrinth encloses three sets of spaces — the 
anterior, middle, and j^sterior ethmoidal cells: they do not communi- 
cate with each other. Externally is the paper-like orbited plette, or os 
planum (lamina papyracea), closing in the middle and posterior cells: 
it articulates in front with the lachrymal, behind with the sphenoid, 
above with the frontal, and below with the superior maxilla and palate 
bones. On this aspect below the plate is a groove belonging to the 
middle meatus of the nose : it turns up anteriorly, and is continued by 
the infundibulum through the anterior ethmoidal cells to the frontal 
sinus; the middle cells open into the horizontal part of the groove. 
The lateral mass in front of the orbital plate is covered in by the lachry 
mal : from this part the uncinate process curves back, down, and out, 



48 BONES OF THE HEAD. 

helping to close the orifice of the antrum : it articulates below with the 
ethmoidal process of the inferior turbinate. 

The inner aspect of each lateral mass is in the outer wall of the nasal 
fossa. Above is a channel, the superior meatus, passing from behind to 
about the middle of the bone : it communicates with the posterior cells. 
The plate overhanging it is the superior turbinate process or superior 
spongy bone (concha sup. ) ; the space above that is in the roof of the 
nose. Below the groove is the inferior turbinate process of the ethmoid 
or middle spongy bone (concha inf.), rolling convexly toward the nasal 
fossa : it forms the lower border of the lateral mass. 

Two grooves cross the upper margin of the lateral mass, forming with 
the frontal the two internal orbital canals. Posteriorly the mass is 
ankylosed with the sphenoidal spongy bone. 

The cribriform plate occupies the ethmoidal notch of the frontal. It 
presents the olfactory groove on each side of the crista galli and foramina 
for the olfactory nerves ; the foramina of the middle set are few and are 
simple perforations; in the external and internal sets they are more 
numerous, and are orifices of small canals which subdivide on the vertical 
plate and lateral mass. Anteriorly is a fissure close to the base of the 
crista galli, and external to it a notch connecting with the anterior in- 
ternal orbital canal for the passage of the nasal nerve and anterior eth- 
moidal artery from the orbit to the cranium, and thence to the nasal 
fossa. 

BONES OF THE FACE. 

Describe the superior maxillary bone. 

The superior maxilla is the principal bone of the face, supporting the 
upper teeth of one side, helping to form the hard palate, floor of orbit, 
floor and outer wall of nasal fossa. There are a body and four processes 
for description. The body is a hollow half-cylinder, presenting an ex- 
ternal surface subdivided into an anterior and posterior, an internal and 
superior ; the processes are nasal, alveolar, malar, and palatal. 

The body encloses the antrum of Highmore, which opens into the 
middle meatus of the nose, The superior maxilla articulates with nine 
or ten bones — with its fellow, with the nasal. frontal, lachrymal, ethmoid, 
palate, malar, vomer, inferior turbinate, and sometimes with the sphe- 
noid at the outer extremity of the spheno-maxillary fissure. The anterior 
or facial surface is marked below by eminences corresponding to fangs 
of the teeth. Internal to the eminence for the canine is the incisor or 
myrtiform fossa; external to it is the deeper canine fossa; above the 
latter, below the margin of the orbit, is the infraorbital foramen. The 
inner margin of this surface is cut by the nasal notch, the sharp edge of 
which is prolonged into the anterior nasal spine. 

The posterior or zygomatic surface looks into the zygomatic and spheno- 
maxillary fossae: it presents two or more apertures of the posterior den- 
tal canals; below and posteriorly is a rough tuberosity. At the junction 



BONES OF THE FACE. ID 

of this surface with the nasal and orbital is a small triangular space on 
which the orbital process of the palate rests, the palatine trigone (lienle). 

The internal or nasal surface presents in front the inferior turbinate 
crest : below it is the smooth concavity of the inferior meatus ; above it 
a small surface forming the atrium (entry) of the middle meatus. Be- 
hind the nasal process is the lachrymal groove, •] inch long, inclined 
down and out, opening into the inferior meatus ; the groove is converted 
into the canal of the nasal duct by the lachrymal and inferior turbinate. 
Behind it is the opening of the antrum; above this are small half-cells 
belonging to the middle ethmoidal set. Behind the opening of the an- 
trum the surface is rough for articulation with the palate bone, and trav- 
ersed by a groove running down and forward, forming with the palate 
the posterior palatine canal. 

The orbital surface is triangular and flat ; externally is a rough surface 
for the malar ; internally is first the lachrymal notch, and behind it a 
pretty straight margin for the ethmoid and orbital process of the palate. 
The postero-external border is free and bounds the spheno-maxillary fis- 
sure. The infraorbital groove commences w T ell back on this surface, lead- 
ing to a canal of the same name which opens anteriorly at the infraorbital 
foramen : from the canal are given off the anterior and middle dental 
canals in the substance of the bone. 

The nasal process projects up, in, and back ; its external surface is 
smooth ; the hinder part of the inner surface completes the anterior eth- 
moidal cells ; below this the surface is crossed by the superior turbinate 
crest (agger nasi) for the inferior turbinate process of the ethmoid (mid- 
dle spongy bone). The anterior border articulates with the nasal bones 
and above with the frontal ; posteriorly is a continuation of the lachrymal 
groove, bounded internally by a sharp edge articulating with the lachry- 
mal, and externally by a smooth border : where this border joins the orbital 
surface is the lachrymal tubercle. 

The alveolar process is thick and hollowed into eight alveoli. The 
malar process is triangular, continuous in front and behind with the 
facial and zygomatic surfaces of the body. Superiorly it is rough for 
the malar : the inferior border forms a thick buttress opposite the first 
molar. 

The palate process with its opposite forms three-fourths of the hard 
palate. Above it is concave transversely, and forms part of the floor 
of the inferior meatus. Below it is arched, and shows lateral grooves 
for nerves and vessels : its posterior extremity falls short of that of the 
alveolar arch and the space is filled by the palate bone. The inner 
border rises into a nasal crest which receives the vomer; in front a more 
elevated part is the incisor crest, prolonged into the anterior nasal spine. 
By the side of the incisor crest is a foramen, becoming a groove : when 
the bones are united there is one orifice Wow, with right and left 
branches above, called the incisor foramina or foramina of Stenson, for 
the transmission of arteries (Fig. 3). The lower aperture is the anterior 
palatine fossa ; in the middle line, opening into it, are the foramina of 
4 —A. 



50 



BONES OF THE HEAD. 



Scarpa, the left nasopalatine nerve passing through the anterior one 
and the right through the posterior. From the anterior palatine fossa 
are seen two sutures passing to the interval between the canine and lat- 

Fig. 3. 

Ant.pa/ctHri c 
\ Canal 



of Slensorv, 



orarrverv 
'' of Sctzrpa, 




Posl.jialaMne (JaruU/ 



Accessory j>alalinc- 
Jfyrairicji 



The Palate and Alveolar Arch. 



era! incisor tooth ; the sutures are to be seen in the inferior meatus. 
They mark off the intermaxillary hone, and include the whole thickness 
of the alveolar processes, the nasal spine, and sockets for incisor teeth. 
No trace of the suture is seen on the facial surface, as an outgrowth, the 
incisor process, forms the front wall of the incisor sockets. 

The maxillary sinus, or antrum, is irregularly pyramidal; the base is 
at the nasal surface of the body and the apex extends into the malar 
process. Its aperture is closed in part by the uncinate process of the 
ethmoid, the ethmoidal process of the inferior turbinate, and the maxil- 



BONES OF THE FACE. 51 

lary process of the palate behind ; the lachrymal in front rarely assists. 
The alveolus of the first molar is most prominent in the floor. 

Describe the palate bone. 

This bone is L -shaped, and forms the back part of the hard palate and 
the lateral wall of the nose between the superior maxilla and internal 
pterygoid plate. It presents a horizontal, a vertical plate, and three 
processes. It articulates with six bones — its fellow, the superior maxilla, 
the ethmoid, sphenoid, vomer, and inferior turbinate. Ihe horizontal 
or palate plate is concave above in the nasal fossa: near its posterior 
border is a transverse ridge for the tensor palati muscle. The posterior 
border is free and concave, gives attachment to the soft palate, and is 
prolonged internally into the posterior nasal or palatine spine, which 
continues the nasal crest of the superior maxillae supporting the vomer. 
It is grooved externally by the posterior palatine canal. The vertical 
plate is thin; its nasal surface is divided into two parts by the inferior 
turbinate crest for the inferior turbinate bone; the middle meatus is 
above it and the inferior below. At the upper part is the superior 
turbinate crest for the middle spongy bone, and above this a groove in 
the superior meatus. The external surface presents above and behind 
a smooth surface, forming the inner wall of the pterygo-maxillary fissure, 
and leads to the posterior palatine groove. In front of the groove the 
surface is applied to the superior maxilla and sends the maxillary pro- 
cess forward. Behind the groove the surface articulates beloAV with the 
maxilla and above with the pterygoid process. 

The pyramidal I process or tuberosity juts out behind and fits in between 
the pterygoid plates: it presents posteriorly a smooth middle district en- 
tering into the pterygoid fossa : internal to it is a groove for the internal 
pterygoid plate, and externally a rough area for the external plate. 
Part of the tuberosity appears in the zygomatic fossa. Interiorly, close 
to the horizontal plate, are the posterior and external accessory palatine 
canals. 

The orbital process rests on the anterior margin of the vertical plate : 
it has five surfaces, three articular, and two, the superior and external, 
are free. 

The superior surface forms the posterior angle of the floor of the 
orbit ; the external looks into the spheno-maxillary fossa ; the anterior 
articulates with the maxilla, the internal with the ethmoid, and the pos- 
terior with the sphenoid. The process is usually hollow, and completes 
a posterior ethmoidal cell or may open into the sphenoidal sinus. 

The sphenoidal process curves up and in from the posterior part of 
the vertical plate ; it has three surfaces : the superior is in contact with 
the under surface of the body of the sphenoid, and is grooved for the 
ptery go-palatine canal; the internal surface looks into the nasal fossa 
and touches the ala of the vomer ; the external looks into the spheno- 
maxillary fossa. 



52 BONES OF THE HEAT). 

The spheno-palatine notch is between these two processes, converted 
by the body of the sphenoid into a foramen of the same name. 

The posterior palatine canal may be wholly confined to the palate bone. 
The spheno-palatine notch may be converted to a foramen by union of the 
sphenoidal and orbital processes. The orbital process may be enlarged by a 
separate ossification from the ethmoid or sphenoid. 

Describe the vomer. 

The vomer (ploughshare) is thin and quadrilateral, and placed verti- 
cally between the nasal fossae. The upper and posterior borders, the 
anterior and inferior, are of nearly equal lengths. It articulates with 
six bones — the sphenoid, ethmoid, two palate, two superior maxillary — 
and with the septal cartilage of the nose. 

Each surface presents a groove leading the naso-palatine nerve to the 
foramen of Scarpa. The superior border divides into two alse, which 
receive the rostrum of the vomer between them ; each ala meets the 
vaginal process of the sphenoid and the sphenoidal process of the 
palate. 

There are usually three vomero-basilar canals — a median, between ala and 
rostrum for nutrient vessels ; an upper lateral one, between the body of 
sphenoid and root of vaginal process, carrying vessels to the sphenoidal cells ; 
a lower lateral one, between the body of sphenoid and sphenoidal process of 
palate, carrying vessels and nerves from the nasal and spheno-maxillary fos- 
sae to the upper pharynx. 

The anterior border is grooved in its lower half for the septal cartilage ; 
in its upper half it is ankylosed on one or both sides, usually the right, 
with the perpendicular plate of the ethmoid. At the inferior anterior 
angle is a short vertical edge to fit in behind the incisor crest of the 
maxillae : from its upper end a process runs forward in the groove of 
the crest, and from its lower end a point may project down between the 
incisor foramina. The inferior border articulates with the nasal crest of 
the maxillae and palate bones : the posterior border is thin and free and 
separates the posterior nares. 

Describe the malar bone. 

This cheek-bone separates the orbit from the temporal fossa and ar- 
ticulates with four bones — the frontal, sphenoid, temporal, and superior 
maxillary. It is quadrangular, with the angles directed vertically and 
horizontally : it may be thought of as formed of a triangular orbital plate 
united at a sharp angle to a quadrangular malar plate. The outer sur- 
face presents a little below the centre the malar tuberosity, and above 
this the orifice of the malar canal. The inner surface is concave, looks 
into the temporal and zygomatic fossae, and presents a roughness for ar- 
ticulation with tlic superior maxilla. The upper angle or frontal process 
is serrated for the external angular process of the frontal. The temporal 
border behind this is sinuous and continuous with the upper border of 
the zygoma. 



BONES OF THE FACE. 53 

The posterior angle or temporal process has the zygoma resting upon 
and articulating with it. The postero-inferior border, the masseteric, 
completes the lower edge of the zygomatic arch ; the anteroinferior 
border, maxillary, and a rough part of the inner surface, articulate with 
the malar process of the superior maxilla. The orbital border is exca- 
vated, and forms a great part of the orbital margin, ending internally 
just above or inside the infraorbital foramen. From this the orbital 
process projects back, forming the fore part of the outer wall of the orbit, 
articulating with the great wing of the sphenoid. On the orbital surface 
are the openings of two canals — the temporal opening on the temporal 
surface, and the malar opening on the facial : they transmit the tem- 
poro-malar branches of the superior maxillary nerve. 

A horizontal suture may divide the bone into two unequal parts. The 
canals may have a common opening on the orbital surface. There may be a 
marginal process at the upper part of the temporal border (more often on the 
right side) for attachment of a band of temporal fascia. The anterior ex- 
tremity of the spheno-maxillary fissure may be completed in one of three 
ways: by the malar in more than half the cases, by the articulation of the 
sphenoid with the superior maxilla, or by a Wormian bone. 

The antrum of Highmore may extend into the malar. 

Describe the nasal bones. 

The two form the bridge of the nose, and each articulates with four 
bones — the frontal, superior maxillary, ethmoid, and its fellow. They 
are narrow and thick above, broader and thinner below. They articulate 
above with the inner part of the nasal notch of the frontal. 

The inferior border is free, and gives attachment to the lateral nasal 
cartilage : it usually has a small notch near the inner end. The ex- 
ternal border is longest, and articulates by means of small teeth with the 
nasal process of the superior maxilla. 

The internal border meets its fellow in a somewhat irregular internasal 
suture, which commonly deviates to one side at the upper end. Pos- 
teriorly the two form a crest which rests from above down on the nasal 
process of the frontal, the vertical plate of the ethmoid, and the septal 
nasal cartilage. The facial surface is convex below and concave above, 
and presents vascular foramina. 

The posterior surface is concave, and a little external to its centre is a 
longitudinal groove for the nasal nerve. 

These bones are relatively large in white races, small and flat in the black 
and yellow races. The internasal suture is obliterated in apes. There may 
be small internasal bones at the lower extremity of the internasal suture. 

Describe the lachrymal bone. 

The lachrymal, or os unguis, is a thin scale like a finger-nail at the an- 
terior and inner part of the orbit. It articulates with four bones — 
frontal, ethmoid, superior maxilla, and inferior turbinate. Its external 
surface is divided by a vertical ridge, the lachrymal crest : in front of it 



54 HONKS OF THE HEAD. 

is the lachrymal groove, and this part is prolonged below as the descend- 
ing process to articulate with the inferior turbinate ; behind the crest the 
surface is smooth and forms part of the orbit, and it is produced below 
into the hamular process, which comes forward in the lachrymal notch 
of the superior maxilla and bounds the outer side of the orifice of the 
nasal duct. The internal surface is a depressed furrow completing above 
some of the anterior ethmoidal cells, and below it looks into the middle 
nasal meatus. 

This bone may be absent, perforated, or divided into pieces ; the hamular 
process may be wanting, small, or so long as to extend upon the face. A 
separate ossicle may take its place, the lesser lachrymal bone. 

Describe the inferior turbinate bone. 

The inferior turbinate or spongy bone projects like a shell into the 
nasal cavity, separating the middle from the inferior meatus. Its con- 
vexity looks in and its lower margin is rolled on itself. Its attached 
margin articulates in front with the inferior turbinate crest of the supe- 
rior maxilla, and then ascends abruptly as the lachrymal process to com- 
plete the lachrymal canal. Behind this, and nearer the back than the 
the front, the bone is folded down as the maxillary process, looking 
over the aperture of the antrum, and forming part of its inner wall : on 
the upper border of this process is the ethmoidal process, which articu- 
lates with the uncinate of the ethmoid. Posteriorly, the bone is attached 
to the inferior turbinate crest of the palate : the posterior extremity is 
elongated and pointed, the anterior flat and broad. 

The bone articulates with the superior maxilla, lachrymal, ethmoid, 
and palate. No muscle is attached to it. The negro may have four tur- 
binate bones. 

Describe the inferior maxillary bone. 

The lower jaw, or mandible, is the strongest bone of the face, and 
articulates with the glenoid fossae of the temporals. It consists of a 
curved horizontal portion or body and two ascending branches or rami. 
The body shows in front a faint vertical ridge, the symphysis of two 
originally distinct pieces: this expands into the mental protuberance, 
which becomes prominent on each side inferiorly as the mental tubercles. 
The superior or alveolar border is hollowed out into sockets for teeth. 
The inferior border, or base, is thick and rounded, and projects beyond 
the superior. Below the incisor teeth is the incisor fossa ; more exter- 
nally is the mental foramen midway between the upper and lower bor- 
ders, under the interval between the two bicuspids : it is the anterior 
opening of the dental canal. Below the foramen the external oblique 
fine runs up and back from the mental tubercle to the anterior margin 
of the ramus. The deep surface of the body presents inferiorly near the 
symphysis an oval fossa for the attachment of the digastric muscle : 
above it are the mental spines, the lower being a median ridge for the 
genio-hyoid muscles, and the upper a pair of tubercles for the genio- 



THE SKULL AS A WHOLE. Ob 

hyoglossi : there may be four tubercles ( I '. ) or two ( • • ) or a vertical 
I ) or one prominence ( • ). Above them a small foramen pene- 
trates the bone and above this a narrow median groove marks the sym- 
physis. Below the mental spines, and passing up and back to the ramus, 
is the internal oblique line or mylo-hyoid ridge, for the mylo-hyoid muscle 
and a slip of the superior constrictor of the pharynx. Above this line is 
a fossa for the sublingual gland, and below it another for the submax- 
illary. 

The ramus is thinner than the body, and where its posterior border 
meets the base it forms the slightly everted angle. The external surface 
is flat, and near the angle it shows oblique lines for tendinous attach- 
ment of the masseter muscle. At the centre of the internal surface, on 
a level with the crowns of the molar teeth, is the inferior dental foramen, 
leading to the dental canal: the inner margin of the foramen is sharp 
anteriorly, and called the lingula mandibulce. Beginning at the notch 
behind the lingula is the mylo-hyoid groove (sometimes a canal), termi- 
nating below the hinder end of the mylo-hyoid ridge. Behind this is a 
roughness for the internal pterygoid muscle. On the upper border of 
the ramus are two processes — the condyle for articulation and the coro- 
noid for muscular attachment : they are separated by the semilunar or 
sigmoid notch. The condyle passes up from the posterior part of the 
ramus, supported on a constricted neck, on the front of which internally is 
a depression for the external pterygoid muscle. One-third inch (8 mm. ) be- 
low the articular surface there may be an external tubercle for the external 
lateral ligament. The condj r le is convex, transversely elongated, and the 
axes of the two would meet at the anterior margin of the foramen mag- 
num. The coronoid process passes up from the fore part of the ramus, in- 
clined out and somewhat beak-shaped : by its apex, sharp margins, and 
inner surface it gives attachment to the temporal muscle. 

The anterior border of the ramus shows three oblique ridges — an ex- 
ternal one to the end of the external oblique line ; internal to that is a 
groove bounded posteriorly by a ridge passing from the internal oblique 
line to the middle aspect of the coronoid ; at the lower part of the 
groove, extending a short distance to the outer side of the alveolus, is 
the third or buccal line. 

The lower jaw consists of a thick shell of compact tissue enclosing cancel- 
lous tissue ; the dental canal in its posterior two-thirds lies close to the inner 
compact layer ; it is prolonged beyond the mental foramen under the canine 
and incisor teeth. There may he two dental canals. The angle of the jaw 
in the adult is about 120°, infancy 140° or more ; in old and toothless jaws it 
is increased. These changes are due to development, absorption of alveolar 
arch, and strength of masseter muscles. 

THE SKULL AS A WHOLE. 
Describe the sutures. 
The skull-bones are closely fitted by uneven edges, there being inter- 



56 BOXES OF THE HEAD. 

posed a little fibrous tissue continuous with the periosteum ; the den- 
tations are confined to the external table, the edges of the inner table 
lying only in apposition. The lower jaw has a movable articulation, 
differing from the others. The sutures around the parietal bones have 
special names: between the two is the sagittal, behind them the lamb- 
doid, in front of them the coronal. 

All the sutures may be arranged in three groups — a median longi- 
tudinal, a lateral longitudinal, and a vertical transverse. The first con- 
sists of the sagittal, and in the infant the frontal ; the second begins in 
the median line in front, and includes on each side the fronto-nasal, 
fronto-maxillary, fronto-lachrymal, fronto-ethmoidal, fronto-malar, fronto- 
sphenoidal, spheno-parietal, squamo-parietal, and masto-parietal ; the 
third comprises the coronal and sphenosquamous, the lambdoid and 
occipito-mastoid, and also the transverse sutures at the base of the 
skull. 

Sometimes the great wing of the sphenoid, the parietal, the squama, and 
the frontal hones do not meet, and the short spheno-parietal sntnre is not 
formed ; the froutal and squama unite in a vertical fronto-temporal suture 
continuing the coronal: this is the rule in the gorilla and chimpanzee. In 
this situation is often developed the epipteric bone. 

After about thirty years of age many sutures close, union taking place on 
the inner surface first: the parts to close first are the sagittal suture between 
the parietal foramina and the lower ends of the coronal suture. 

THE WORMIAN BONES. 

These, ossa triquetra, ossa suturarum, are irregular ossifications between 
cranial bones rarely found in the face. They are usually symmetrical, and 
are most common in the lambdoid suture, occupying the place of the superior 
angle of the occipital bone; may be at either anterior angle of the parietals. 
They usually include only one plate of the skull. 

The ossiculum jugular e may be found at the jugular foramen. 

EXTERNAL SURFACE OP THE SKULL. 

The external surface may be divided into superior, inferior, anterior, 
and lateral regions. 

Describe the superior region. 

This extends from the supraorbital margins to the superior curved 
line of the occiput, bounded laterally by the temporal lines. It is a 
smooth, convex surface covered by muscle and aponeurosis. The great- 
est transverse diameter of the skull is at the junction of the posterior 
and middle thirds — viz. 5§ inches (140 mm.) ; the greatest longitudinal 
diameter from the under margin of frontal bone to the external occi- 
pital protuberance is 6f inches (170 mm. ). As the head is usually held 
it makes an angle of 20° with the horizon. 

Describe the anterior region. 
This region presents the openings of the orbits, the bridge of the nose, 



EXTERNAL SURFACE OF THE SKULL. 57 

below that the anterior nasal aperture (apertura pyriformisY presenting 

the anterior nasal spine below. Below the aperture are the incisor fossae 
of the upper jaw. below the orbits the canine fossae, and external to 
them the malar prominences. The lower jaw completes the skeleton of 
the face with its incisor fossae, mental prominence, etc. 

In a nearly vertical line on either side are three foramina for the exit 
of some part of the three divisions of the fifth cranial nerve — viz. the 
supraorbital, infraorbital, and mental. There are also the malar for- 
amina on the malar bone. 

The nose is rarely placed in the centre of the face, and the nasal aper- 
ture is often unsymmetrical, a deflection of the septum occurring toward 
the wider half. 

Describe the orbits. 

The orbits are pyramidal fossae, somewhat quadrilateral, witli their 
bases turned out and forward : their inner walls are nearly parallel, and 
their outer walls diverge at nearly right angles to each other. Each is 
formed of seven bones, or eleven for the two — the frontal, sphenoid, 
malar, superior maxillary, lachrymal, ethmoid, and palate. The roof 
of each is formed by the orbital plate of the frontal and small wing of 
the sphenoid; the floor by the malar, superior maxilla, and orbital plate 
of the palate ; the inner wall by the nasal process of the superior 
maxilla, the lachrymal, ethmoid, and body of the sphenoid ; the outer 
wall by the malar and great wing of the sphenoid. The sphenoidal 
fissure at its inner part occupies the apex of the orbit ; its outer ex- 
tremity lies between the roof and outer wall. 

The optic foramen is internal to and above the fissure. In the angle 
between the external wall and floor is the spheno-maxillary fissure, 
bounded by the palate, superior maxilla, malar, and sphenoid bones: 
it leads into the spheno-maxillary fossa at its back part and zygomatic 
fossa at its fore part. Passing forward from the margin of this fissure 
is the commencement of the infraorbital canal. On the inner wall in 
front is the lachrymal groove, leading to the canal of the nasal duct, and 
farther back, between the frontal and ethmoid, are the anterior and 
posterior internal orbital canals. At the inner margin of the roof is the 
supraorbital foramen or notch. Within the external angular process is 
the lachrymal fossa, and on the outer wall are the temporal and malar 
canals. 

Describe the lateral region of the skull. 

This presents from behind forward the mastoid portion, the mastoid 
foramen, the external auditory meatus, the glenoid fossa with condyle 
of lower jaw, eminentia articularis, coronoid process, and zygomatic arch. 
Above this arch is the temporal fossa, and below it, separated by the 
infratemporal crest, is the zygomatic fossa. 

The temporal fossa, occupied by the temporal muscle, is bounded 
above by the temporal crest of the frontal and the lower temporal line 



58 BOXES OF THE HEAD. 

of the parietal : the latter runs into the supramastoid erest, and that 
into the zygomatic arch. 

The zygomatic or infratemporal fossa contains a part of the temporal 
muscle, the external and internal pterygoids, the internal maxillary artery, 
and the inferior maxillary nerve. Some of its boundaries are indefinite : 
externally is the ramus of the lower jaw ; superiorly the great wing of the 
sphenoid, showing the foramen ovale and spinosum, also a small part of 
the squamous portion of the temporal ; anteriorly is the lower part of 
the malar and zj'gomatic surface of the superior maxilla ; the inferior 
limit is the extremity of the external pterygoid plate and alveolar border 
of the superior maxilla. The inner wall is formed by the external ptery- 
goid plate ; the posterior limit is the eminentia articularis and posterior 
border of the pterygoid plate. 

Inferiorly the pterygoid process approaches close to the superior 
maxilla, but is prevented from meeting by the pyramidal process of the 
palate. Above they are separated by the pterygo-maxillary fissure, 
leading into the spheno-maxillary fossa. Running at right angles to the 
fissure is the spheno-maxillary fissure opening into the orbit. 

Describe the spheno-maxillary fossa. 

This is a small triangular space at the angle of junction of the above- 
named fissures, placed beneath the apex of the orbit. It is bounded 
above by the body of the sphenoid, in front by the superior maxilla, 
behind by the base of the pterygoid, and internally by the vertical plate 
of the palate. It has three fissures terminating in it — the sphenoidal 
spheno-maxillary and pterygo-maxillary. It communicates with four 
fossae — the orbital, nasal, zygomatic, and middle fossa of the base of 
the skull ; and has opening into it five foramina — three from behind, 
the foramen rotundum, the Vidian, and the pterygopalatine canals; 
internally is the spheno-palatine foramen, and inferiorly the posterior 
palatine canals, and occasionally the accessory posterior palatine canals. 

Describe the external base of the skull. 

("Base of skull " properly means base of the cranium, and does not 
include the facial bones ; we have followed, however, the usual descrip- 
tion, and include the inferior maxilla.) 

It is divisible into three parts — anterior, middle, and posterior. The 
anterior division consists of the palate, alveolar arches, and body of the 
inferior maxilla. It is traversed longitudinally by a median suture, and 
transversely by that between the maxillary and palate bones. In front 
is the anterior palatine fossa, with the four foramina opening into it; 
farther back are the under surface of the tuberosity of the palate, the 
apertures of the posterior and external palatine canals, and the posterior 
nasal spine. 

The middle division extends back to the foramen magnum, and is 
called the guttural fossa (relating to the throat). ^ In the mid-line is the 
basilar process, and in front of that the body of the sphenoid covered 



EXTERNAL SURFACE OF THE SKULL. 59 

by the alae of the vomer. On each side the petrous portion reaches to 
the extremity of the basilar process, and between the petrous and 
squamous is the back part of the great wing of the sphenoid. In front 
are the posterior nans or choance (funnels), separated by the vomer, 
bounded above by the sphenoid, below by the horizontal plates of the 
palate bones, and laterally by the internal pterygoid plates. On each 
side are the pterygopalatine and Vidian canals, the scaphoid and ptery- 
goid fossae. A line from the external pterygoid plate to the spine of the 
sphenoid separates this surface from the zygomatic fossa : internal to this 
line is the groove for the cartilaginous part of the Eustachian tube. 
Between the apex of the petrous, the basilar process, and the sphenoid 
is the foramen lacerum. (This is the only foramen properly called 
''lacerated.") This with the petro-basilar fissure is filled with fibrous 
tissue, and may contain Wormian bones. Passing back and out from 
this is the petro-sphenoidal fissure, the styloid and vaginal processes, 
and the stylo-mastoid foramen ; more internally are the anterior condylar 
foramina and the jugular fossa. This fossa is divided into three com- 
partments by processes of dura mater. The inferior petrosal sinus is in 
the anterior one, the lateral sinus, some ascending pharyngeal and occi- 
pital arteries in the posterior one, and the ninth, tenth, and eleventh 
cranial nerves in the middle one. 

Other points have been described with the temporal bone. 

The posterior division presents on either side of the foramen magnum 
the occipital condyle, jugular process, occipital sulcus, digastric fossa, 
and mastoid process. Behind the foramen magnum is the tabular part 
of the occipital up to the superior curved line. Into this posterior divis- 
ion are inserted all the muscles running up to the skull from the ribs, 
spines, and transverse processes. 

Henle describes for base of skull the base of the cranial bones : the foramen 
magnum is where the vertebral canal broadens out into the cranium ; behind 
it is the part corresponding to the vertebral arches, in front the part corre- 
sponding to the vertebral body. The line of separation passes through the 
mastoid and jugular processes, the condyles, and the foramen magnum. In 
front of this line are two other regions: the "middle girdle" nearly corre- 
sponds to the middle fossa of the interior ; its anterior border goes on either 
side from the pharyngeal spine, in front of the pterygoid process to the outer 
extremity of the crista orbitalis, which is the upper border of the spheno- 
maxillary fissure. 

The anterior portion in front of the pharyngeal spine forms the roof of the 
"vegetative tube." 

Describe the interior of the cranium. 

The inner table presents impressions for cerebral convolutions. The 
thickness of the skull-cap, or calvaria, is i to i inch. The base of the 
skull varies in thickness, thinnest at the cribriform and orbital plates, 
where there is no diploe ; also thin in the inferior occipital fossa, in the 
squama, and glenoid fossa. The inner surface of the calvaria is dome- 
like, formed by the frontal, parietal, and occipital bones. It is marked 



GO BONES OF THE HEAD. 

by the superior longitudinal sulcus, small meningeal grooves, and Pac- 
chionian fossae. The only apertures are the inconstant parietal foramina. 

Describe the internal base of the' skull. 

This surface is divided into three fossae — anterior, middle, and poste- 
rior. 

The anterior fossa is formed by the orbital plates of the frontal, the 
cribriform of the ethmoid, the small wings and part of the body of the 
sphenoid : it supports the frontal lobes of the cerebrum. It is convex 
laterally, with a hollow over the cribriform plate, where the crista galli 
stands up separating the olfactory grooves. There is here the foramen 
caecum, the olfactory foramina, openings of the internal orbital canals, 
and the foramen for the nasal nerve. 

The middle fossa is on a lower level than the anterior, and consists of 
a median and two lateral parts. The median part is narrow, presenting 
the olivary eminence, the sella Turcica, and limited behind by the dor- 
sum sellae. Laterally is the great wing of the sphenoid, the squama, 
and antero-internal surface of the petrous portion. This lodges the tem- 
poral lobe of the cerebrum. The foramina present are the optic, sphe- 
noidal fissure, foramen rotundum, ovale, spinosum, lacerum, and hiatus 
Fallopii. 

The posterior fossa, is deeper and larger than the others, and lodges 
the cerebellum, medulla, and pons. The occipital bone, the petrous 
and mastoid portions, postero-inferior angle of the parietal, and body of 
the sphenoid enter into it. In the centre is the foramen magnum, and 
on each side, in a nearly vertical line, are the anterior condylar foramen, 
jugular foramen, and internal auditory meatus. Behind the jugular 
foramen is the posterior condylar (if present), and higher up the mas- 
toid foramen, both opening into the lateral sulcus. By the internal 
auditory meatus the facial and auditory nerves, the portio intermedia, 
and the auditory vessels leave the cranium. 

What grooves are there for blood-vessels? 

That for the middle meningeal artery commences at the foramen 
spinosum, and passes anteriorly to the great wing of the sphenoid, and 
posteriorly upon the squama and parietal. There is also the groove for 
the internal carotid artery on the side of the body of the sphenoid, the 
groove for the superior longitudinal sinus terminating at the internal 
occipital protuberance, those for the lateral sinuses, and others for the 
superior and inferior petrosal sinuses on the petrous portion. 

Describe the nasal cavities and communicating air-sinuses. 

The nasal fossa" arc placed one on each side of a median vertical sep- 
tum. They open in front by the anterior nasal aperture and behind by 
the posterior nares. They communicate with the sinuses of the frontal, 
ethmoid, sphenoid, and superior maxillary bones. They are narrow 
transversely, especially above. The internal wall, or septum nasi, is 



INTERNAL SURFACE OF THE SKULL. fil 

formed by the perpendicular plate of the ethmoid, the vomer, nasal 
spine of the frontal, crests of the nasal, rostrum of sphenoid, crests of 
the maxillary, and palate bones. There is an angular deficiency in front, 
tilled by the septal cartilage, which usually deviates to one side. 

The roof is horizontal in the middle part and sloping in front and be- 
hind. The middle part is formed by the cribriform, the fore part by the 
nasal and frontal bones, the back part by the body of the sphenoid, the 
ala of the vomer, and sphenoidal process of the palate. In the angle 
formed by the cribriform and body of the sphenoid is the spheno-eth- 
moidal recess: the sphenoidal sinus opens upon its posterior wall. 

The floor is formed by the palate processes of the maxillary and 
palate bones; it is smooth and concave transversely, and shows the 
orifice of the incisor foramen. The external wall is formed by the 
nasal, superior maxillary, lachrymal, ethmoid, inferior turbinate, palate, 
and internal pterygoid plate. The superior and inferior turbinate 
processes of the ethmoid and the inferior spongy bone overhang the 
three meatuses. The superior meatus is very short, and placed be- 
tween the superior and inferior turbinate processes; into it open in 
front the posterior ethmoidal cells, and behind the spheno-palatine 
foramen. The middle meatus is above the inferior spongy bone, and 
communicates w T ith the anterior and middle ethmoidal cells, with the 
maxillary sinus, and in front by the infundibulum with the frontal 
sinus. The inferior meatus, longer than the others, lies between the 
inferior spongy bone and the floor of the cavity ; in front is the orifice 
of the nasal duct. 

The Air- Sinuses. 

These communicate with the nasal cavities by narrow orifices : with 
the exception of the maxillary sinus (antrum) they are not present at 
birth. In old age they increase in size by absorption of neighboring 
cancellated tissue. The antrum begins to be formed about the fourth 
month. The frontal, ethmoidal, and sphenoidal excavate their respective 
bones in childhood, and at puberty undergo a great enlargement. Their 
purpose may be for resonance. They have been sufficiently described 
with the different bones. 

OSSIFICATION OF THE BONES OF THE HEAD. 

Ossifications at the base of the cranium take place for the most part in car- 
tilage ; those of the roof of the skull and of the face originate in membrane, 
excepting the inferior turbinate and part of the lower jaw. Tbc diploe and 
air-sinuses are absent at first. 

The occipital bone consists of four pieces at birth — a basilar, tabular, and two 
condylar parts. The basilar and condylar parts have each one nucleus ; in 
the tabular part tbere are usually four, the upper pair deposited in membrane 
and representing the interparietal bone of animals. This subdivision may 
exist in the human skull. 

The parietal bone begins to ossify in membrane at the seventh week : it has 



62 BONES OF THE HEAD. 

two centres, which speedily unite into one mass at the position of the. future 
parietal eminence. The radiating ossification leaves a notch in front of the 
upper posterior angle, giving rise when united to its fellow to the sagittal f on - 
tanelle. This closes during foetal life, but the parietal foramina are remains 
of the interval. Sometimes & parietal fissure persists. The two centres may- 
develop separately. 

The ■frontal bone is developed from two centres in membrane, appearing at 
the seventh week. At birth the bone consists of two lateral portions : the 
frontal suture ossifies from below upward, usually during the second year. 
The frontal sinuses appear about the seventh year and increase to old age. 

The fontanelles are membranous intervals between the incomplete angles 
of the parietal and neighboring bones, They are six in number— two median 
and four lateral. The anterior is quadrangular, placed between four bones, 
with its most acute angle pointing toward the nose; the posterior is trian- 
gular, is filled at birth, but the bones are freely movable. The lateral ones, 
are irregular intervals at the inferior angles of the parietal. All traces of 
them should disappear before the age of four. 

The temporal bone late in fcetal life consists of three parts — squamo-zygo- 
matic, petro-mastoid, and tympanic — developed from ten centres : the squarno- 
zygomatic is developed in membrane from a single centre. From the squa- 
mosal a post-auditory process grows down between the tympanic and petro- 
mastoid portions, and forms the upper part of the mastoid division of the bone. 
In the third month a nucleus appears in the membranous wall of the tym- 
pauum and forms the tympanic ring, an imperfect circle open above and en- 
closing the tympanic membrane. The petro-mastoid, or ear-capsule, is de- 
veloped in cartilage. 

The styloid process is formed from two centres in cartilage: the one near 
the extremity remains small till puberty, not joining the other till adult life 
or remaining separate. At birth the mastoid portion is flat, the antrum is 
present, the glenoid fossa shallow, the tympanic ring and membrane are even 
with the outer surface of the bone. The external auditory meatus is devel- 
oped by an outward projection of the tympanic ring, commencing as two 
tubercles : these meet on the floor of the meatus, enclosing a foramen which 
is not obliterated till the fifth year. This part always remains thin, or a small 
aperture may persist. 

The sphenoid is divided in the foetus into a post-sphenoid part, to which 
the sella Turcica, great wings, and pterygoids belong, and a presphenoid part, 
which includes the body in front of the olivary eminence and the small 
wings. It has twelve centres in all, one for each pterygoid plate, each lin- 
gula, each carotid groove. The sphenoidal spongy bones begin to ossify at the 
fifth month. They entirely surround the sphenoidal sinus by the third year ; 
then their upper and inner parts absorb. They are ankylosed first to the 
ethmoid (fourth year) ; hence some regard them as parts of that bone; they 
join the sphenoid at the ninth to twelfth year. 

The ethmoid has three centres, one for each lateral mass and one for the ver- 
tical plate ; the cribriform comes from all three sources. 

The superior maxilla, clavicle, and lower jaw begin to ossify at about the 
same time, fifth to the seventh week. The number of centres is uncertain, but 
there seem to be four pieces — a malar portion, orbito-facial, palatine, and a 
premaxillary for the bone carrying the incisor teeth. The antrum appears at 
the fourth month. The infraorbital canal begins as a groove, which is closed 
by the growing over of the outer margin : a fine suture remains to indicate 
the line of meeting. 

The palate bone has a single centre. 



EXTERNAL SURFACE OF THE SKULL. 63 

The vomer has two nuclei in membrane ; they unite below, but above and 
in front form two laminse. 

The nasal and lachrymal bones each have a separate centre: the lateral car- 
tilage of the nose continues up beneath the nasals ; it subsequently disappears. 

The malar bone has three centres: a continued separation of one of them 
gives rise to a bipartite bone occasionally seen. 

The inferior turbinate has a single, centre in cartilage at the fifth month. 

The inferior maxillary bone is developed in the fibrous tissue investing 
Meckel's cartilage: the largest part is formed in membrane outside this car- 
tilage. A small part of the body near the symphysis ossifies directly from 
Meckel's cartilage; the condyle, part of the ramus, and the angle also ossify 
in cartilage, the last not connected with Meckel's, which runs up to the fissure 
of Glaser continuous with the slender process of the malleus, and it eventu- 
ally forms the internal lateral ligament of the lower jaw. 

What are some of the points of difference between human and 
animal skulls? 

(1) The proportionally large expansion of the cranial bones in the human 
skull ; (2) the smaller development of the face and jaws, all of which are 
under the brain-case; (3) adaptation of the cranium to the erect posture. 
The occipital condyles are at a point about ^ 6 of the distance from the 
posterior to the anterior extremity of the head, but this part is heavier 
than the anterior, and therefore nearly balanced. The foramen magnum 
looks down ; in quadrupeds it is posterior and looks back ; in anthropoid apes 
it is intermediate in direction. The downward openings of the nostrils, 
forward aspect of the orbits, vertical forehead, and oval face are in strong 
contrast with the small cranium and strong crests of the animal. In late 
years the vertebrate theory of the skull tends to be abandoned. 

What are some of the various forms of skull ? 

According to Age : in the foetus the posterior part is large and the face is not 
one-eighth of the cranial bulk, while in the adult it is one-half. The skull 
grows rapidly during the first seven years; at puberty there is a second period 
of growth affecting face and air-sinuses. 

Sexual Differences : the female skull is smaller, smoother, and lighter than 
the male; the cranial cavity is less by one-tenth. 

Race Differences : the capacity normally varies from 60 to 110 cubic inches 
(1000 cc. to 1800 cc), with an average in all races of 85 cubic inches (1400 cc). 

Skulls exceeding 87 cubic inches (1450 cc.) are megacephalic — Europeans 
and Eskimos. 

Skulls below 80 cubic inches (1350 cc.) are microcephalic — Australians. 

Skulls between 80 and 87 cubic inches (1350 and 1450 cc.) are mesocephalic — 
Chinese. 

What are the names of certain fixed points on the skull ? 

Alveolar point, centre of upper alveolar arch. 
Subnasal point, middle of anterior nasal aperture. 
Xasion, middle of naso-frontal suture. 

Ophryon, middle of that supraorbital line which separates the face from the 
cranium. 

Bregma, point of junction of coronal and sagittal sutures. 
Obelion, point in the sagittal suture between the parietal foramina. 
Lambda, point of junction of sagittal and lambdoid sutures. 
Occipital point, median point of occiput most removed from glabella. 



64 BONES OF THE UPPER EXTREMITY. 

Tnion, external occipital protuberance. 

Opislhion, middle of posterior margin of foramen magnum. 

Basion, middle of anterior margin of foramen magnum. 

Pterion, spheno-parietal suture. 

Lower stephanion, where lower temporal line crosses the coronal suture. 

Upper stephanion, where the upper temporal line crosses the coronal suture. 

Asterion, lateral angle of occipital bone. 

Auricular point, centre of orifice of external auditory meatus. 

What are some of the measurements of the cranium ? 

Maximum circumference (horizontal), 21.7 inches (550 mm.); minimum, 
17.7 inches (450 mm.); average in adult European male, 20.5 inches (525 
miii. i, in female, 19.5 inches (500 mm.). 

The proportion of the breadth to the length on a scale of 100 is the cephalic 
index : 

Skulls with a breadth-index above 80 are brachycephalic. 

Skulls with a breadth-index from 75 to 80 are mesaticephalic. 

Skulls with a breadth-index below 75 are dolichocephalic. 

The breadth is usually taken as four-fifths the length. 

The gnathic index expresses the degree of projection of the jaws. Similarly, 
there are the nasal index, orbital index, etc. Irregularities of form are a result 
of too early ossification of sutures : scaphocephaly is a result of obliterated 
sagittal suture; acrocephaly is due to obliterated coronal suture; plaaiocephaly 
is oblique deformity. 

BONES OF THE UPPER EXTREMITY. 

Shoulder j La^uh f ' ^ ormm S shoulder-girdle. 
Arm (brachium), humerus. 
Upper limb, - Forearm (antibrachium), radius and ulna. 

{ carpus. 
Hand (manus) \ metacarpus. 

( phalanges. 

THE SHOULDER. 
Describe the clavicle. 

The clavicle (key) passes out, back, and slightly upward from the sum- 
mit of the sternum to the acromion, and connects the upper limb to the 
trunk. It is curved like the letter./' for purposes of elasticity and ad- 
mission of vessels behind it. The inner curve is convex forward, and 
occupies two-thirds of the bone: this part is prismatic. The outer third 
of the bone is concave in front and is flattened from above down. 

The superior surfaces of these two portions are continuous; the infe- 
rior surfaces arc continuous ; the anterior border of the outer portion 
runs into the anterior surface of the inner; and the posterior border of 
the outer is continuous with the posterior surface of the inner. The 
superior surface is broad externally and largely subcutaneous; at its cen- 
tre it may present a canal for the supraclavicular nerve ; the sterno-cleido- 






THE SHOULDER. 65 

mastoid is attached to the inner part. The anterior surface is reduced 
to a rough border on the outer portion, where it gives attachment to the 
deltoid, and may present a deltoid tubercle. The pectoralis major is 
attached to the inner half. 

The posterior surface is a border externally and gives attachment to 
the trapezius. In the middle of this surface is the orifice of a medul- 
lary canal directed outward. (In bones having but one secondary centre 
the medullary artery runs from it. ) Internally this surface gives part 
attachment to the sterno-hyoid muscle. 

The inferior surface shows internally a rough impression or costal 
tuberosity about 1 inch long, for the rhomboid ligament ; internal to it is 
a small facet for articulation with the cartilage of the first rib ; external 
to it, a groove passing beyond the middle third for the subclavius mus- 
cle : the groove may show a longitudinal ridge for an intermuscular sep- 
tum. On the posterior border, at the junction of the outer and middle 
thirds, is the conoid tubercle (scapular tuberosity), and passing out and 
forward from it the trapezoid line. 

The sternal end is thick and projects in an angle down and backward, 
its triangular concavo-convex surface looking a little downward and for- 
ward. The scapular end is so bevelled as to rest upon the acromion, the 
small articular surface looking down and out : this end is normally a 
little higher than the acromion on which it rests. 

This bone is a fulcrum to enable muscles to give lateral motion to the arm : 
it is absent in animals whose fore limbs are used only for progression — e. g. 
horse and bear; in carnivora it is not attached to bone ; it is the furculum or 
" wish-bone " of birds. The female clavicle is smoother and more slender 
than the male. The right clavicle is usually rougher and shorter than the 
left. It is developed from two centres : one is the earliest in the body to ap- 
pear, fifth week, and the secondary centre at the sternal end is the last in the 
body to appear, twentieth year. 

Describe the scapula. 

The scapula (spade) extends from the second to the seventh rib or 
seventh interspace. It is attached to the trunk only by muscles, is ar- 
ticulated with the clavicle, and from it is suspended the humerus in the 
shoulder-joint: its posterior border is about ] inch from, and parallel 
with, the vertebral spines ; its anterior surface looks forward, down, and 
in. The bone consists of a large triangular blade or body, and two pro- 
cesses, the coracoid and spine, and presents for examination two surfaces, 
three borders, and three angles. The anterior surface, or venter, pre- 
sents the subscapidar fossa, marked by three or four converging oblique 
lines, giving attachment to tendinous intersections of the subscapular 
muscle. The deepest part of the fossa is the subscapular angle, where 
the bone seems bent on itself, so that the thickest part of the muscle is 
perpendicular to the plane of the glenoid cavity, and can act most advan- 
tageously. Separated from this fossa are two flat surfaces, one at the 
upper angle and one at the lower : with the line connecting them close to 
the vertebral border they give attachment to the serratus magnus muscle. 
5— A. 



66 BONES OF THE UPPER EXTREMITY. 

The posterior surface, or dorsum, is divided by the spine into two 
unequal fossae, the supraspinous and infraspinous. The supraspinatus 
muscle rises from the inner two-thirds of the upper fossa. The lower 
fossa is marked near the centre by a convexity corresponding to the 
concavity of the venter ; on either side of this is a groove, the external 
one being deep and bounded by the axillary border. Near the inner 
border are short lines for intermuscular septa of the infraspinatus mus- 
cle, which rises from the inner two-thirds and covers the outer third. 
Along the outer part of this surface is a ridge passing down and back to 
the inner border, about 1 inch above the inferior angle : it gives attach- 
ment to the aponeurosis between the infraspinatus and teres muscles. On 
the upper third of the narrow surface between this line and the axillary 
border is a groove for the dorsalis scapulae vessels ; the middle third and 
part of the upper give attachment to the teres minor. Below this, in- 
cluding the inferior angle, is a raised surface for the teres major, over 
which the latissimus dorsi glides or attaches a few fibres. An oblique 
line separates the origins of the two teres muscles. 

The spine, of the scapula is a triangular plate projecting back and up 
from the dorsum. Beginning near the upper fourth of the vertebral 
border, it passes up across the dorsum to the middle of the neck of the 
scapula, and turns forward into the acromion process. The upper and 
lower surfaces are concave and form parts of the two dorsal fossae. It 
has two unattached borders, a posterior subcutaneous one and an exter- 
nal axillary one. The former rises from the vertebral border by a tri- 
angular surface, over which a tendon of the trapezius glides as it passes 
to its insertion into a rough tubercle beyond. (This tubercle is very large 
in animals. ) The rest of this border is rough and serpentine, and gives 
attachment by a superior lip to the trapezius, by an inferior lip to the 
deltoid. The external border is short, smooth, and concave, enclosing 
the great scapular notch. 

The acromion process projects out and forward over the glenoid fossa : 
it is compressed from above down ; its superior surface is rough, subcu- 
taneous, and continuous with the prominent border of the spine. An- 
teriorly on its inner border is an oval articular facet for the clavicle : to 
this border is attached the trapezius, to the outer border the deltoid, 
marked by three or four tubercles for tendinous septa. This outer 
border terminates posteriorly in the acromial angle. The coraco- 
acromial ligament is attached to the apex of the acromion. 

The coracoid process rises at first almost vertically from the upper 
border of the head, compressed from before backward : it then bends at 
a right angle forward and outward. Superiorly, toward its base, is the 
origin of the conoid ligament, and the trapezoid rises from an oblique 
line running forward and outward. The coraco-acromial ligament is at- 
tached to the outer border, the conjoined tendon of the coraco-brachialis 
and biceps to its apex, and the pectoralis minor to its inner border. The 
tip of the coracoid is about one and a half inches distant from the apex 
of the acromion. 






THE ARM. 67 

The external angle of the scapula is the thickest part of the bone : it 
is called the head, supported on a neck. The head bears the glenoid 
cavity : this is slightly concave, looks outward, forward, and slightly up- 
ward. It is pyriform, with its narrow end above, and measures If inches 
by \\ inches (40 mm. by 30 nun.). Above it is a supra glenoid tubercle 
for the long head of the biceps. The "anatomical neck" is the part 
just behind the head. 

The superior angle of the scapula is thin and rounded, and gives at- 
tachment to some fibres of the levator anguli scapulae. 

The inferior angle is thick and rough for the teres major attachment, 
sometimes the latissimus dorsi. 

The superior border is shortest, and extends from the superior angle 
down to the coracoid, at the base of which is the suprasccqmlar or 
coraco-scapular notch. A line through the suprascapular and great 
scapular notches marks the "surgical neck" of the bone. 

The axillary border is the thickest. Beneath the glenoid fossa is a 
rough tubercle or ridge, infraglenoid, over an inch long, for the long 
head of the triceps. On the ventral aspect of this border is a longitu- 
dinal groove from which the subscapular muscle rises in part. 

The vertebral border is the longest, and gives attachment above the 
triangular surface at the apex of the spine to the levator anguli muscle, 
opposite the triangular surface to the rhomboideus minor, and below 
this to the rhomboideus major. 

The body of the scapula is mostly thin and translucent, and has no can- 
cellated tissue in those spots. Vascular foramina pierce the upper and lower 
surfaces of the spine and the anterior surface near the neck. The human 
scapula is remarkable for its length. All mammals possess scapula?. The 
coracoid reaches to the sternum in birds. 

The bone is developed from seven centres and is ossified in two principal parts, 
one for the body and one for the coracoid, which represents the large coracoid 
bone of lower vertebrates. The various epiphyses should be joined to the 
bone at the age of twenty-five. Sometimes the acromion and spine do not 
unite, and a joint with hyaline cartilage and synovial membrane may here 
be present. 

THE ARM. 

Describe the humerus. 

The arm-bone extends from the shoulder to the elbow. It is divisible 
into an upper extremity, including head, neck, great and small tuber- 
osities, a shaft, and inferior extremity, which includes condyles, epi- 
condyles, and articular surface. The head forms one-third of a sphere 
of \\ inches (32 mm.) radius, but the margin is not a true circle: a line 
from the upper part of the articular surface down and back to the lower 
part is 2 inches (50 mm. ). A transverse diameter at right angles to this 
is If inches (44 mm.). The head is directed up, in, and a little back- 
ward, and makes an angle of 140° with the shaft. The " anatomical 



68 BONES OF THE UPPER EXTREMITY. 

• 

neck" is the slight constriction at the circumference of the articular sur- 
face ; the "surgical neck" is below the tuberosities. 

The great tuberosity is a thick projection starting up from the external 
surface of the shaft. It is marked above by three facets, the upper for 
the supraspinatus tendon, the next for the infraspinatus, and the lowest 
for the teres minor, which also is attached to the shaft to the extent of 
1 inch. Separated from this tuberosity by the bicipital groove (inter- 
tubercular sulcus, f inch (10 mm.) broad) is the small tuberosity, looking 
forward and inward and giving attachment to the subscapulars. 

The shaft is thick and cylindrical above, expanded transversely and 
three-sided below. It is divided into external, internal, and posterior 
surfaces by anterior and lateral borders.^ (Henle describes it as having 
two surfaces and two borders.) Superiorly is the bicipital groove lodg- 
ing the long tendon of the biceps and a branch of the anterior circum- 
flex artery. This groove, descending, is bounded by rough margins, the 
external or 'pectoral ridge (spina tuberculi majoris) for the pectoralis 
major muscle, and the internal for the latissimus dorsi and teres major 
muscles: these muscular attachments end at the junction of the upper 
with the lower three-fourths. 

The anterior border is the pectoral ridge continued to the coronoid de- 
pression below. It becomes rounded and smooth below, and gives at- 
tachment to the brachialis anticus muscle. 

The inner border is the inner bicipital ridge continued to the inner 
condyle, called below the internal supracondylar ridge. About the 
centre of this border is a rough linear mark for the coraco-brachialis 
muscle, and just below it the orifice of the medullary canal directed 
downward. 

The external border runs from the back part of the great tuberosity 
to the external condyle. Its centre is traversed by the broad spiral 
groove, limited above by the deltoid eminence and below by the external 
supracondylar ridge, The ridge gives origin by its upper two-thirds to 
the supinator longus muscle; hence it is called the supinator ridge, 
which is very large in burrowing animals : its lower third attaches the 
extensor carpi radialis longior. The posterior lip of either supracondylar 
ridge is for the triceps, and a middle portion for intermuscular septa. 
The external surface presents near its middle the deltoid eminence. 

The interned surface is narrow above, and forms the bicipital groove; 
near its centre is the insertion of the coraco-brachialis. Below this level 
the external and internal surfaces are occupied by the brachialis anticus. 

The posterior surface is twisted, so that its upper part is directed a 
little inward, its lower part backward and outward. It is nearly all 
covered by the external and internal heads of the triceps, which are 
separated by the spiral groove running down and out. At the upper 
part of this groove is generally a second medullary foramen for a branch 
of the superior profunda artery. 

The inferior extremity is flattened from before backward and curved 



THE ARM. 69 

slightly forward. The two condyles include the articular surface, sepa- 
rated by a rounded ridge; the inner condyle is five-sixths articular. 
The prominent tuberosities situated on either condyle arc the epicon- 
dyles, developed from separate centres. The internal epicondyle is the 

more prominent one, is inclined backward, and forms posteriorly a shal- 
low groove for the ulnar nerve. It gives attachment to the pronator 
radii teres and the common tendon of the superficial pronato-flexor mus- 
cles of the forearm. 

The external condyle presents (1) the epicondyle, which gives origin 
to some of the supinato-extensor muscles of the forearm ; (2) below and 
internal to this on the condyle a small impression for the anconeus ; and 
(3) a pit for the external lateral ligament. 

The inferior articular surface is divided into two parts : the external 
part, rounded and directed forward, is the capitellum for articulation 
with the radius ; it does not extend at all on the posterior surface. In- 
ternal to it is a groove for the inner margin of the head of the radius. 
The internal portion, or trochlea, articulates with the ulna, and extends 
from the anterior to the posterior surface of the bone ; the external bor- 
der is rounded and corresponds to the internal between the radius and 
ulna. The internal border is thick and prominent. Anteriorly these mar- 
gins are inclined down and inward, posteriorly up and outward, so that 
the groove is obliquely inclined from without inward, and if continued 
would form the thread of a screw. The external part of the trochlea is 
the segment of a sphere, the internal part the segment of a truncated 
cone with base internal ; at the junction of the cone and sphere is the 
groove. 

Above the trochlea posteriorly is the olecranon fossa, above it ante- 
riorly the coronoid fossa : the thin plate between them may be perforated 
by the supratrochlear foramen. This occurs more often in the lower 
races of man and in the gorilla. Above the capitellum is the radial 
fossa for the head of the radius in flexion. 

The average length of the adult male humerus is 13 inches, female, 12 
inches. It is nearly one-fifth the height of the individual. The right hume- 
rus with the radius is usually i to I inches longer than the left ; no differ- 
ence at birth. 

The shaft of the humerus is twisted through about 135°. The twist is seen 
at the spiral groove, " groove of torsion," which does not exist in the foetus ; 
this allows the hand to serve the purposes of the head and mouth. A small 
hooked supracondylar process is sometimes found about 2 inches above the 
inner epicondyle. A fibrous band connects it to the inner epicondyle and 
gives origin to the pronator radii teres muscle; through the arch beneath 
pass the median nerve and brachial artery. 

Remains of this foramen are seen in a fibrous band connected with the 
pronator muscle in about 45 per cent, of cases. 

The humerus is developed from seven centres ; the upper epiphysis unites 
last. 



70 BONES OF THE VPPER EXTREMITY. 

THE FOREARM. 
Describe the ulna. 

This is the internal of the two bones of the forearm. A line passing 
from the tuberosity of the humerus through the capitellum touches the 
lower end of the ulna. It is the arm-bone, while the radius is the hand- 
bone. 

The wpper extremity presents two processes and two articular concav- 
ities. The great sigmoid cavity, articulating with the trochlea, looks 
upward and forward, and is bounded above by the olecranon and below 
by the coronoid processes', it is concave from above down, and is trav- 
ersed by a longitudinal ridge which is a half-circle of f inch ( 1 mm. ) 
radius. The part external to the ridge is broad and convex above, the 
part internal is broad and concave below. A slight constriction is seen 
across the middle of the cavity. Continuous with it is the small sigmoid 
cavity on the outer side of the base of the coronoid : it is concave from 
before backward for the head of the radius. The olecranon terminates 
in front in a beak which overhangs the great sigmoid cavity ; behind it 
is a rectangular tuberosity, forming the point of the elbow. It has supe- 
riorly a ligamentous district, next a bursal, and next a tendinous one for 
the triceps. The posterior surface of the olecranon is triangular and sub- 
cutaneous, and continuous with the posterior border of the ulna. The 
extremity of the coronoid process is sharp and pointed. Its superior sur- 
face is a part of the great sigmoid cavity. At the inner part of the junc- 
tion of the coronoid to the shaft of the ulna, also to the tuberosity of 
ulna at the angle of junction, is attached the brachialis anticus muscle, 
not into the process. Arising from the process is one head of the flexor 
sublimis digitorum, the flexor profundus, pronator radii teres, and occa- 
sionally the flexor longus pollicis. 

The shaft or body tapers from above, is three-sided in its upper three- 
fourths, slender and cylindrical in its lower fourth. The upper three- 
fourths are convex backward ; it is also convex externally above and in- 
ternally below. The anterior border passes from the inner edge of the 
coronoid to the front of the styloid : it is thick and rounded, and gives 
attachment to the flexor profundus digitorum, and in its lower fourth to 
the pronator quadratus. 

The posterior border begins below the olecranon, and runs with a 
sinuous curve to the back of the styloid. It is ill defined below and sub- 
cutaneous throughout, and affords attachment to an aponeurosis common 
to three muscles — the flexor carpi ulnaris, extensor c. ulnaris, and flexor 
profundus. The external or interosseous border is a sharp edge in the 
middle three-fifths of the shaft. Below it is faintly marked. The upper 
one-fifth is continued by two lines passing to the extremities of the small 
sigmoid notch : the posterior line is prominent, supinator ridge, for the 
supinator brevis muscle. 

The anterior surface is concave above, and gives origin to the flexor 
profundus digitorum : the lower one-third is marked by the oblique pro- 



THE FOREARM. 7 I 

nator ridge^ which joins the anterior border. Above the middle is a 
medullary foramen directed upward. 

The internal surface is smooth, and gives attachment to the flexor 
profundus digitorum muscle : it is subcutaneous in the lower one-third. 
Iihe posterior surface looks outward and backward: an oblique line de- 
scending from the supinator ridge to the posterior border at the junction 
of its upper and middle thirds marks oif a triangular area for the an- 
coneus muscle. The ridge itself gives attachment to the supinator 
brevis. Below this is a longitudinal ridge dividing the surface into a 
smooth inner portion covered by the extensor c. ulnaris, and an outer 
part impressed from above downward by the extensor ossis metacarpi 
pollicis, extensor secundi internod. poll., and extensor indicis. 

The inferior extremity presents a rounded head: from its inner and 
back part there projects downward the styloid process, giving attachment 
to the internal lateral ligament and to the triangular hbro-cartilage. Be- 
tween the head and styloid process is a groove for the tendon of the ex- 
tensor carpi ulnaris. 

The head has two articular surfaces — an inferior one, upon which the 
triangular fibro-cartilage plays, and an outer narrow convex o*ne, for the 
sigmoid cavity of the radius. With the hand supine the styloid process 
projects at the inner and back part of the wrist : if pronated, the outer 
and fore part of the ulnar head is prominent between the tendons of the 
extensor c. ulnaris and extensor min. digiti. 

The ulna is developed from three centres : the greater part of the 
olecranon grows by an extension from the shaft. 

Describe the radius. 

This bone articulates with the humerus, ulna, scaphoid, and semilunar 
bones. The superior extremity, or head (eminentia capitata), is disk- 
shaped. On its summit is a depression for the capitellum of the hume- 
rus. It is surrounded by a convex part, broadest internally, which rotates 
in the small sigmoid cavity of the ulna within the orbicular ligament. 
The head is supported by a neck, which presents behind a ridge for part 
of the insertion of the supinator brevis. 

The shaft is larger below than above, slightly curved, and convex out- 
ward and backward. Antero-internally below the neck is the bicipital 
tuberosity, rough posteriorly for the insertion of the biceps, and smooth 
in front for a bursa. Below this tuberosity the shaft has three surfaces 
and three borders. 

The anterior border extends from the tuberosity to the base of the 
styloid: its upper part is called the anterior oblique line, and gives at- 
tachment to the supinator brevis, flexor longus pollicis, pronator radii 
teres, and flexor sublimis. 

The posterior border runs from the back of the neck to the posterior 
part oi the base of the stvloid. It is well marked only in its middle 
third. 

The internal or interosseous border becomes prominent below, and at 



72 BONES OF THE UPPER EXTREMITY. 

its lower part divides into two ridges which meet the margins of the 
sigmoid cavity, analogous to the division of a like border of the ulna. 

The anterior surface is grooved longitudinally for the flexor long. poll, 
muscle: at the lower end is a flattened impression for the pronator 
quadratus, which also rises from a small surface at the inner side of the 
bone. A medullary foramen is above the middle of this surface. 

The posterior surface shows at the junction of the upper and middle 
thirds the posterior oblique line, below which is attached the extensor 
ossis metacarpi poll., and below that the extensor prinii internodii 
poll. The external surface is convex, and marked near the middle by 
an impression for the pronator radii teres : above this, on the area be- 
tween the anterior and posterior oblique lines, is inserted the supinator 
brevis. 

The lower extremity of the radius, broad and quadrilateral, presents a 
carpal articular surface and an ulnar articular surface. The former is 
divided by a line into a quadrilateral inner part for the semilunar, 
and a triangular outer part for the scaphoid. The articular surface 
for the ulna or sigmoid cavity is at right angles to the inferior surface, 
and concave from before backward. To the smooth border between 
these two articular surfaces is attached the base of the triangular fibro- 
cartilage. Externally the styloid process projects downward. Ante- 
riorly a transverse ridge forms the lowest limit of the pronator quad- 
ratus impression, which is continued into a vertical ridge external to 
that impression : between this ridge and the scaphoid facet is a tri- 
angular area for a strong band of the anterior ligament, The ex- 
ternal and posterior aspects are marked by the following grooves from 
without inward : a flat groove for the extensor ossis met. poll, and ex- 
tensor prim, internod. (next descends the styloid process) ; a broad 
groove, subdivided by a slight ridge, for the extensor carpi rad. longior 
and brevior ; an oblique narrow groove, bounded externally by a tubercle, 
for the extensor secundi internod. poll. ; a broad groove for the extensor 
indicis, extensor communis, and extensor min. dig. Just above the first 
groove is an impression for the supinator longus. 

The relative length of the forearm to the arm is expressed by the humero- 
radial index: Eskimo, 71 (i. e. the radius is 71 if the humerus be taken as 
100) ; European, 74 ; gorilla, 80; orang, 100. The index is higher in the foetus 
and infant. The radius in bats and birds is very long and supports the wing. 
The radius is developed from three centres. All the epiphyses around the 
elbow unite earlier than those at the opposite ends of the bones. 

THE HAND. 

The skeleton of the hand consists of three segments — wrist-bones, 
bones of palm, and bones of fingers. 

Describe the carpus, or wrist-bones. 

The carpus is composed of eight short bones arranged in two rows : 
the upper row, from radial to ulnar side, comprises the scaphoid, lunar 



THE HAND. 73 

(semilunar), pyramidal (cuneiform), and pisiform; in the inferior row- 
are the trapezium, trapezoid, os magnum, and unciform. The dorsal 
surface of the carpus is convex, and palmar concave transversely; the 
concavity is bounded by four prominences (eminentise carpi), one at each 
end of each row, to which the anterior annular ligament is attached. 
The superior surfaces of the scaphoid, lunar, and pyramidal form a me- 
niscus for articulation with the concavity presented by the radius and 
triangular fibro-cartilage. The mid-carpal articulation is concavo-con- 
vex, the trapezium, trapezoid, and os magnum forming a concavity 
for the scaphoid, while the unciform and head of the os magnum rise 
up in a convexity. Each bone is more or less cubical and presents six 
surfaces. 

The scaphoid (boat-like) has its long axis directed down and out. 
Internally it has two articular facets, a lower one for the os magnum and 
an upper crescentic one for the lunar. The superior .surface is smooth 
and triangular, passes farther back than forward, and articulates with 
the radius. The inferior surface is smooth and convex, divided by a 
ridge, articulating externally with the trapezium and internally with the 
trapezoid. The anterior surface is concave above, and presents a conical 
tuberosity below. The external surface is rough and narrow. The pos- 
terior surface is a narrow transverse groove. 

The lunar bone is characterized by a deep concavity from before back- 
ward on its inferior surface ; it is for the head of the os magnum. This 
surface also presents a long narrow facet for the unciform. Externally 
it is crescentic and vertical for the scaphoid. Its internal surface looks 
down and in, is narrower than the external, and articulates with the 
pyramidal. The convex upper surface is four-sided, articulates with 
the radius, and extends farther back than forward, so that the anterior 
free surface is deeper than the posterior. 

The pyramided (cuneiform) bone directs its blunted apex down and 
in. The base shows a flat quadrilateral surface for the lunar. The in- 
ferior surface is concavo-convex from without inward, and articulates 
with the unciform. The anterior surface has a small articular facet on 
its inner half for the pisiform. The supero-posterior surface has near 
the base an articular facet for the triangular fibro-cartilage, but is mostly 
rough for ligaments. 

The pisiform (like a pea) is anterior to the other bones of the carpus. 
It is spheroidal, with longest diameter directed vertically. Posteriorly is 
is an oval facet for the pyramidal, leaving a free portion below. The 
inner surface is convex and rough ; the outer, toward the flexor tendons, 
is smoother and slightly concave. 

The trapezium (a table) is the most external of the second row. The 
supero-internal surface is concave and articulates with the scaphoid. 
The inferior surface, directed down and out, is concavo-convex for the 
first metacarpal. The internal surface articulates with the trapezoid, 
and on its lower inner angle with the second metacarpal. The anterior 
surface is marked by a vertical groove for the flexor carpi radialis tension, 



74 



BONES OF THE UPPER EXTREMITY. 



external to which is a ridge or tuberosity for the annular ligament. The 
anterior, external, and dorsal surfaces are free. 

The trapezoid is much smaller than the trapezium ; its longest diam- 
eter is from before backward, and its posterior surface is larger than its 
anterior. The external inferior angle of the anterior surface is pro- 
longed backward between the smooth surface for the trapezium and that 
for the second metacarpal bone. The superior surface is quadrilateral 
and articulates with the scaphoid ; the external is convex for the tra- 
pezium ; the internal articulates with the os magnum ; and the inferior 
concavo-convex surface with the second metacarpal. Hold the bone 
with the larger non-articular surface toward you and the smooth quadri- 
lateral articular surface upward (for scaphoid) ; the convex articular sur- 
face (for the trapezium) will point to the side to which the bone belongs. 

The os magnum (os capitatum) is the largest of the carpal bones, rec- 
tangular below and rounded above. The upper extremity, or head, ar- 
ticulates with the lunar, its smooth surface extending farther behind than 
in front, and prolonged upon its outer side for the scaphoid. The )ieck 
is formed by depressions anteriorly and posteriorly. The anterior surface 
is narrower than the posterior. The posterior surface projects down- 
ward at its internal inferior angle. Externally, below the surface for the 
scaphoid, is a facet for the trapezoid. On the posterior part of the in- 
ner surface is a vertical facet for the unciform. Interiorly there are three 
facets, the middle being the larger, for the second, third, and fourth 
metacarpal bones. 

The unciform (hook-like) bone is wedge-shaped, with its base or infe- 
rior surface resting on the fourth and fifth metacarpal bones : its apex 
points up and out and articulates with the lunar. The external surface 
is vertical, and articulates with the os magnum by its upper posterior 
part. Its supero-internal surface is concavo-convex for the pyramidal : 
it is separated from the inferior surface by a rough border. The anterior 
surface at its lower and inner side presents the unciform process, pro- 
jecting forward and curved slightly outward. 

ARTICULATIONS OF CARPAL BONES. 



Scaphoid . 

Lunar . . 

Pyramidal 

Pisifmn 
Trapezium 

Trapezoid. 



Superior. External. 



radius 
radius 



free 
scaphoid 



triangular lunar 

fib. cart, j 
free ] free 

scaphoid free 



scaphoid trapezium 

Os magnum scaphoid trapezoid 

| lunar 

Unciform. . lunar ios magnum 



Inferior. 



Internal. 



Ante- 
rior. 



trapezium os magnum free 

trapezoid lunar 
os magnum pyramidal free 

unciform 
unciform free pisi- 

form 
free i free free 

1st metacarp. trapezoid free 

1 2d metacarp 
2d metacarp. 'os magnum free 
2d,Hd, and 4th I unciform free 

metacarp. I 
3d and 4th pyramidal free 

metacarp. I 



Posterior. 



free 

free 

free 

pyramidal 
free 

free 
free 

free 



Num- 
ber. 



THE HAND. 75 

The carpus is wholly cartilaginous at birth: each bone is developed from a 
single centre except the scaphoid. The nucleus of the pisiform does not ap- 
pear till the twelfth year, the latest of all primary centres. In the foetus the 
scaphoid has normally a second cartilaginous element, which may develop 
into the os centrale placed on the back of the carpus between the scaphoid, os 
magnum, and trapezoid. The styloid process of the third metacarpal may be 
separated as a supernumerary bone. 

Describe the metacarpus, or bones of palm. 

The metacarpus supports the fingers and consists of five long, slightly 
divergent bones. They form the segment of a transverse arch : their 
carpal extremities are expanded bases and their digital ends are rounded 
heads. The first metacarpal is broad and short, the second longest of 
all, while the third, fourth, and fifth decrease regularly in length. The 
shafts are curved longitudinally, and are three-sided, presenting a pos- 
terior surface and anteriorly a median margin between tw r o lateral sur- 
faces. They are more slender near the carpal ends and thicker toward 
the heads. The dorsal surface is triangular, being bounded by lines 
which proceed from the sides of the head and converge in the second, 
third, and fourth metacarpals opposite the middle of the carpal extremity. 
The heads articulate with the proximal phalanges : their smooth surfaces 
broaden and extend farther on the palmar than on the dorsal aspect, 
On each side is a tubercle, with a hollow below it for attachment of the 
lateral ligament. The carpal extremities present distinctions. The first 
bone has a saddle-shaped articular surface, and 'externally a prominence 
for the insertion of the extensor ossis metacarpi poll. The shaft is com- 
pressed and dorsal surface convex. On the palmar surface the rounded 
ridge is nearer the inner than the outer border. The carpal extremity 
of the second is notched for the trapezoid. On the radial side is a facet 
for the trapezium, and close to it an impression for the extensor carp, 
rad. long. A prominent ulnar lip with two long facets is the distinguish- 
ing feature. The third bone presents a styloid process on the posterior 
radial angle, passing up behind the os magnum, and below it an impres- 
sion for the extensor carp. rad. brev. The radial side has one facet and 
the ulnar side two. The carpal extremity of the fourth has two facets 
on the radial side, and a concave semielliptical one on the ulnar side. 
The fifth has a saddle-shaped surface for the unciform, and a tuberosity 
on the ulnar side for the extensor carpi ulnaris. There is only one oblique 
ridge on the dorsal surface, extending from the radial side of the head 
to the ulnar side of the base. 

The first metacarpal articulates at its base with 1 bone. 

The second metacarpal articulates at its base with 4 bones. 

The third metacarpal articulates at its base with 3 bones. 

The fourth metacarpal articulates at its base with 4 bones. 

The fifth metacarpal articulates at its base with 2 bones. 

It is interesting that the corresponding metatarsals articulate with ex- 
actly the same number. 



ib BONES OF THE LOWER EXTREMITY. 

Describe the digital phalanges. 

The phalanges (intcrnodia) arc fourteen in number, three for each 
finger and two for the thumb. Those of the first row, five in number, 
are slightly curved. The dorsal surface is transversely convex, while 
the palmar is flat and bounded by rough margins. Their metacarpal 
extremities are thick and present a transversely concave surface ; their 
distal extremities are smaller and divided by a median groove into two 
condyles. The bones of the middle row are four in number, and smaller 
than the preceding: their proximal articular surfaces show a middle 
ridge and two lateral depressions. The distal ends are like those of the 
first row. The terminal or ungual phalanges are five in number: their 
proximal extremities are like those of the middle, but with a depression 
in front for the deep flexor. Their free extremities are flat and expanded, 
and raised round the margins of the palmar aspect into an ungual process. 

"Where are the sesamoid bones of the hand? 

One pair, each \ inch (5 mm.) in diameter, is placed in the palmar 
wall of the metacarpo-phalangeal joint of the thumb ; others, single or 
double, may occur in the corresponding joint of the index and little 
fingers, more rarely in the third and fourth. 

Collectively, the phalanges of the middle finger are longest, then those of 
the ring, index, little finger, and thumb. In some hands the index is longer 
than the ring, due wholly to the length of the metacarpal bone. 

The metacarpals and phalanges are formed each from one centre for the 
shaft, and one for an epiphysis. In the four inner metacarpals the epiphyses 
are at the heads; in the metacarpal of the thumb and in the phalanges the 
epiphyses are at the bases. The so-called first metacarpal therefore resembles 
a phalanx. The ungual phalanges are peculiar in beginning to ossify at the 
distal extremities instead of in the middle. In the metacarpals the' medul- 
lary foramen is on the radial side of the palmar surface, and the canal runs 
toward the base ; in the phalanges and first metacarpal the canal runs toward 
the head of the bone. 

BONES OF THE LOWER EXTREMITY. 

The lower limb consists of the haunch or hip, thigh, leg, and foot. 
Tn the haunch is the hip-bone, in the thigh the femur, in the leg the 
tibia and fibula, at the knee a large sesamoid bone, the patella, in the 
foot the tarsus, metatarsus, and phalanges. The pelvis and hip-bone 
are a part of the lower extremity. 

THE PELVIS. 
Describe the hip-bone. 

The hip or innominate bone (os coxae), with its fellow, the sacrum, 
and coccyx form the pelvis. This bone is constricted in the middle and 
expanded above and below ; it has been likened to the shape of a meat- 
chopper. 



THE PELVIS. 77 

The acetabulum is on the outer aspect of the constricted portion, and 
the interior expanded portion is perforated by the thyroid or obturator 
foramen. The bone above forms part of the abdominal wall, and below 
part of the true pelvis. In early life the ilium, pubes, and ischium are 

distinct. 

The ilium {ili<u flanks; ileum is a part of the small intestine) is the su- 
perior expanded portion, and forms less than two-fifths of the acetab- 
ulum. This portion is limited anteriorly and posteriorly by margins 
which diverge at right angles from each other, and superiorly by the 
arched crest of the ilium. In front the crest is concave inward and behind 
it is concave outward : there is a marked external projection in the ante- 
rior third. On the crest are external and internal lips and a median 
ridge. The anterior extremity projects as the anterior superior spine ; 
below it is a concavity, the lesser iliac notch, and below that the anterior 
inferior s})i)ie. Behind, the projecting extremity of the crest is called 
the posterior superior spine, separated by a small notch from the poste- 
rior inferior spine, below which is the great sciatic (ilio-sciatic) notch. 

The external surface or dorsum ilii presents three curved gluteal lines. 
The posterior or superior one commences 2 inches in front of the poste- 
rior superior spine, and curves down and forward to the back part of the 
ilio-sciatic notch. The middle gluteal 7we begins in front about \h inches 
behind the anterior superior spine, and arches back and down to the 
upper part of the notch. The inferior gluteal line, less strongly marked, 
commences just above the anterior inferior spine, and passes back to the 
fore part of the notch. Behind the posterior line is a semilunar surface, 
rough above for the gluteus maximus : the sickle-shaped space between 
the posterior and middle lines and iliac crest is occupied by the gluteus 
medius ; the gluteus minimus is between the middle and inferior lines. 
Just above the acetabulum is an elongated mark for the reflected head 
of the rectus femoris. 

The internal surface is divided into two parts : the anterior part is 
the iliac fossa or venter ilii. To the inner side of the anterior inferior 
spine is a shallow groove, the greater iliac notch, which lodges the ilio- 
psoas muscle : the inner boundary of the groove is the ilio-jjectineal emi- 
nence, marking the junction of the pubis and ilium. The posterior part 
(sacral surface) is again divided, presenting from below upward (1) a 
smooth surface in the true pelvis, separated from the iliac fossa by the 
iliac portion of the ilio-pectineal line ; (2) the auricular surface, for articu- 
lation with the sacrum; (3) depressions on the iliac tuberosity, for the 
posterior sacro-iliac ligament ; (4) a rough surface giving origin to the 
erector and multifidus spinae muscles. 

The iliac crest gives attachment by its outer lip to the tensor vaginae fem- 
oris, obliquus externus, latissimus dorsi, and fascia lata; by its middle ridge 
to the obliquus interims; by its inner lip to the transversalis, quadratus lum- 
borum, erector spina 1 , and iliac fascia. To the anterior superior spine is attached 
externally the tensor vaginae femoris, in front the sartorius, and internally 
Poupart's ligament. From the anterior inferior spine originates the straight 



78 BONES OF THE LOWER EXTREMITY. 

head of the rectus : just below this is an impression for the ilio-femoral liga- 
ment. The iliac part of the ilio-pectineal line gives attachment to the iliac 
and obturator fasciae and tendon of the psoas parvus. 

The os pubis forms the anterior wall of the pelvis, and bounds the 
thyroid foramen above. It forms about one-fifth of the acetabulum : at 
its inner extremity is a long oval surface marked by transverse ridges or 
nipple-like processes for articulation with the opposite bone ; the junc- 
tion is the symphysis pubis. The part passing down and out from the 
symphysis is the descending ramus ; the upper part is the superior or 
ascend 'in g ramus ; and the flat portion between the rami is the body. 
The pelvic surface of the body is smooth, the anterior surface rough. 
The upper extremity of the symphysis is the angle ; extending out from 
this on the superior border is the crest, terminating in the spine. The 
descending ramus' is thin and flat, and joins that of the ischium at the 
jyubo-ischiatic tuberosity. The superior ramus becomes prismatic : its 
superior border is the pubic portion of the ilio-pectineal line, running from 
the spine of the pubis to the ilio-pectineal eminence. The triangular 
surface in front of this line gives origin to the pectineus muscle : below 
is the obturator crest, extending from the nubic spine to the margin of 
the acetabulum. Behind the outer part ot the crest on the inferior sur- 
face of the ramus is the obturator groove, directed from behind forward 
and inward : it is limited by the inferior and superior obturator tubercles. 

The pubic crest gives origin to part of the conjoined tendon, the pyramidalis 
and rectus abdominis. To the pubic spine is inserted Poupart's ligament and 
the outer pillar of the external abdominal ring. From the front of the pubis, 
in the angle between the crest and symphysis, rises the adductor longus mus- 
cle, and below this the adductor brevis and part of the adductor magnus. 
Internal to these the gracilis is attached, and external the obturator externus. 
Posteriorly the pubis gives attachment to the obturator internus : above this 
is sometimes a faint line passing from the upper margin of the obturator for- 
amen to the lower end of the symphysis ; the levator ani muscle is attached to 
it, and the obturator and recto-vesical fasciae. 

The ischium forms the lower and back part of the hip-bone, bounds 
the thyroid foramen below, and forms over two-fifths of the acetabulum. 
It presents a body, and below this a tuberosity continued forward into the 
ramus. The body has three surfaces, external, internal, and posterior. 
The external surface helps form the acetabulum ; below this and above 
the tuberosity is a horizontal groove for the tendon of the obturator ex- 
ternus muscle. The internal surface is smooth, and forms part of the 
wall of the true pelvis. In front it is separated from the iliac fossa by 
the iliac portion of the ilio-pect. line, but behind the junction of the 
ischium and ilium does not reach that line. The posterior surface is 
quadrilateral, getting narrow below, and continuous with the tuberosity. 
It presents a part of the groove for the obturator externus, and sup- 
ports the piriformis, the two gemelli, and the obturator internus. 

On the posterior border is the spine, projecting back and in, and form- 
ing the inferior limit of the ilio-sciatic notch. 



THE PELVIS. 79 

The small sciatic notch is between the spine and tuberosity. The 
tubi rosity presents two lips and an intermediate space. The external lip 
rives attachment to the quadratus femoris and adductor magnus; the 
inner lip to the falciform portion of the great sacro-sciatic ligament, and 
more anteriorly to the transversus perinei and erector penis. The inter- 
mediate space is divided into two portions : the anterior part attaches 
the adductor magnus externally and great sacro-sciatic ligament in- 
ternally ; the posterior part has two facets, an upper and outer for the 
semimembranosus, a lower and inner for the biceps and semitendinosus. 

The ramus joins the descending ramus of the pubis at the inner side 
of the thyroid foramen. Its outer surface gives attachment to the obtu- 
rator externus, adductor magnus, and gracilis. The cms penis, and 
above that the constrictor urethrae, are attached to the inner border. 

The acetabulum, or cotyloid cavity, is cup-shaped, and looks out, 
down, and forward. It is nearly surrounded by a prominent rim which 
presents three depressions — a slight one anteriorly and posteriorly, and 
the cotyloid notch below. In the lateral and upper parts of the cavity 
is a broad horseshoe-shaped articular surface. From the anterior corner 
of the horseshoe run two lines, one up and forward as the obturator 
crest to the pubic spine, the other backward to the superior obturator 
tubercle. The central part of the cup and the notch are depressed 
(fossa acetabuli), and contain fat and the interarticular ligament. This 
non-articular surface belongs mostly to the ischium. 

The thyroid or obturator foramen (foramen ovale) is internal to and 
below the acetabulum. It is nearly oval in the male, more triangular in 
the female. It is closed by fibrous membranes, except in the region of 
the obturator groove in its upper margin. 

The hip-bone is strongest along lines of greatest pressure. There is a thick 
bar on the ilium from the auricular surface to the acetabulum, also a second 
in the ischium and its' tuberosity, and another running up from the acetabulum 
to the most prominent part of the crest. The iliac fossa and floor of the ace- 
tabulum are very thin : vascular foramina perforate the thickest parts of the 
bone. There may be an accessory ischial spine in the great sacro-sciatic 
notch. The pelves of most Javanese women present a preauricular sulcus for 
the anterior sacro-iliac ligament, rarely developed in European women. 

The os innominatum is developed from eight or more centres in three prin- 
cipal pieces. By the seventh or eighth year the three pieces are separated by 
a Y-shaped cartilage in the acetabulum, which begins to ossify by the twelfth 
year from several centres : the most constant gives rise to a triangular os ace- 
tabuli, which forms the whole of the pubic portion of the articular cavity. 
Between the ilium and ischium are some irregular nodules, and a lamina 
spreads over the iliac and ischial portions of the articular surface. Secondary 
centres appear for the crest of the ilium, the tuber ischii, the anterior inferior 
spine, and symphysis: all are joined to the main bone by the twenty-fifth 
year. 

Describe the pelvis as a whole. 

The pelvis (basin) is composed of four bones — two ossa innominata, 
the sacrum, and coccyx. It is divided into two parts by a plane passing 



80 BONES OF THE LOWER EXTREMITY. 

through the sacral promontory, ilio-pectineal lines, and upper border of 
symphysis. This circle is the inlet or brim of the true pelvis: the space 
above it really belongs to the abdomen, but is called the false or upper 
pelvis. The pelvic outlet presents three large prominences, the coccyx 
and tuberosities of the ischia. Beneath the symphysis and between the 
ischial tuberosities is the subpubic arch ; behind the tuberosities are the 
sacro-sciatic notches. 

What is the position of the pelvis ? 

In the erect attitude, with the heels together and toes turned out, the 
plane of the brim forms 60° with the horizontal, that of the outlet 16°. 
The base of the sacrum is about 3* inches above the upper margin of 
the symphysis, and the tip of the coccyx about o inch above the apex 
of the subpupic arch. The sacrum looks down and forward, and is the 
inverted keystone of an arch, as its pelvic surface is broader than the 
dorsal : it is held in place chiefly by ligaments and by a slight bony pro- 
jection into the iliac articular surface (Fig. 12). 

What are the differences according to sex? 

In the female the bones are more slender and muscular impressions 
less marked ; the height is less, breadth and capacity greater ; but the 
false pelvis is relatively narrower than in the male. The sacrum is wider 
and flatter, less prominent, the subpubic arch is wider, about 90° (male 
is 75°), and the space between the ischial tuberosities is greater. The 
thyroid foramen is broader and more triangular in the female, nearly 
oval in the male. 

The characteristics of the human pelvis compared with that of lower ani- 
mals are its shallowness and breadth, great capacity of true pelvis, expansion 
of ilia, straightness of ischial tuberosities, and shortness of symphysis. The 
pelvis of the kangaroo is so small that the young are. born when li inches 
long, and placed in a pouch on the abdomen of the mother, with the nipple 
firmly fixed in their mouths. 

THE SACRUM AND COCCYX. (See False Vertebrce, p. 28.) 

THE THIGH. 
Describe the femur. 

The femur (thigh-bone) is the largest, longest, and strongest bone of 
the skeleton. In the erect position it inclines inward and slightly back- 
ward. It is divisible into a superior extremity, including head, neck, and 
two trochanters; shaft; and inferior extremity, expanded into external 
and internal condyles and epicondyhs. 

The neck extends upward, inward, and slightly forward, being set upon 
the shaft at an angle of 125°. It is compressed from before backward, 
is broad at its base, becomes rounded at its summit, and enlarged as it 
joins the head. It is shorter above and in front than below and behind. 
Posteriorly it usually shows a shallow groove for the obturator externus 



THE THIGH. 81 

tendon. Reasons for a neck are — ( 1) to transmit shock through an arch ; 
(2) room for adductor muscles; (3) room for pelvic muscles to femur. 

The head forms more than half a sphere: its posterior inferior quad- 
rant shows a depression (fossa capitis), the fore part of which gives 
attachment to the interarticular ligament (lig. teres) of the joint. In 
this hollow are one or two vascular foramina. 

The great trochanter (to turn) is a thick process prolonged upward in 
a line with the external surface of the shaft to a level about •] or i inch 
below the head. In front it is marked by a broad depression for the 
gluteus minimus. Externally an oblique line runs downward and for- 
ward, indicating the inferior border of the gluteus medius insertion. 
Lower down is a horizontal line continued to the tubercle of the femur, 
which is situated in front at the junction of the neck with the tuberosity : 
the tubercle is the meeting- place of five muscles — vastus externus, gluteus 
minimus, obturator interims, and two gemelli. Internally, at the base 
of the trochanter and rather behind the neck, is the digital fossa, giving 
attachment to the obturator externus tendon. Above and in front of 
this is the insertion of the obturator internus and gemelli muscles. 

The upper border of the trochanter is narrow, and presents an oval 
mark for the pyriformis. The posterior border is prominent, and con- 
tinuous with the posterior ii iter trochanteric line, limiting the neck poste- 
riorly. Above the centre of this line is the tubercle of the quadratus, 
for attachment of the upper part of the quadratus femoris : sometimes 
a linea quadrati passes vertically down from the tubercle. 

The small trochanter is a pyramidal eminence projecting from the 
postero-internal aspect of the bone at the junction of the neck with the 
shaft. Its apex gives attachment to the ilio-psoas tendon. 

Anteriorly the neck of the femur is separated from the shaft by the 
anterior intertrochanteric line, which is the upper part of the spiral line 
(does not connect the trochanters) : it commences at the tubercle of the 
femur, and runs down and in a finger's breadth in front of the small tro- 
chanter : it gives attachment to the capsular ligament, the united crureus 
and vastus internus muscles. 

The shaft is arched with its convexity forward : toward the middle it 
is partly cylindrical, and expanded below. It presents anterior and lateral 
surfaces without definite lines of demarcation. All these surfaces are 
covered by the crureus and vasti muscles. Behind the lateral surfaces 
are separated by the linea aspera. This is a prominent ridge extending 
along the middle third of the shaft, bifurcating above and below. The 
external lip is prolonged up to the great trochanter : its upper end is 
strongly marked for the gluteus maximus, constituting the gluteal ridge. 
The inner lip winds round below the small trochanter, merging into the 
anterior intertrochanteric line and forming the lower part of the spiral 
line : rising from the inner lip, a third line passes up to the small tro- 
chanter and gives attachment to the pectineus. 

Inferiorly two lips are prolonged to the condyles as the internal and 
external, supracondylar lines ) enclosing the flat popliteal surface of the 
6— A. 



82 BONES OF THE LOWER EXTREMITY. 

femur. The inner line is interrupted where the femoral vessels lie 
against the bone, and terminates below in the adductor tubercle. Above 
the centre of the linea aspera is the medullary foramen, directed upward ; 
a second may exist near the lower end of the bone. 

To the inner lip of the linea aspera is attached the vastus internus, to the 
outer lip the vastus externus, and diagonally between the two the adductor 
magnus. Between the adductor ruagnus and vastus externus are the gluteus 
maxinius and short head of the biceps ; between the adductor ruagnus and 
vastus internus are the iliacus, pectineus, adductor brevis, and adductor 
longus. At the lower part of the popliteal space above each condyle is the 
origin of one head of the gastrocnemius, and externally of the plantaris. 

The inferior extremity presents two rounded condyles, united in front, 
but separated behind by the intercondylar notch: the external is broader 
and more prominent in front, the internal longer and more prominent 
internally. The inner aspect of this condyle and the head of the femur 
face nearly the same direction. 

The inferior surfaces of the two condyles are on the same level in the 
natural position of the femur. Opposite the front of the intercondylar 
notch the whole articular surface is divided by a faint transverse groove 
on either side into three parts — a convex surface on either condyle for 
the tibia and a grooved anterior surface for the patellar. 

The patellar surface is trochlear in form, marked by a vertical hollow 
and two lips: the external portion is wider, more prominent, and rises 
higher. The tibial surfaces are nearly parallel, but the internal one 
turns outward to meet the patellar surface. The exposed lateral surface 
of each condyle presents a tuberosity or epicondyle for ligamentous at- 
tachment. The external is the smaller : above it is the impression for 
the outer head of the gastrocnemius ; below and behind it is an oblique 
groove ending inferiorly in a pit from which rises the popliteus muscle ; 
its tendon sinks fully into the groove only when the knee-joint is flexed. 
The inner head of the gastrocnemius rises from the upper part of the 
inner condyle. 

The intercondylar fossa presents two impressions for crucial ligaments: 
that for the anterior ligament is on the posterior part of the inner sur- 
face of the external condyle ; that for the posterior ligament is on the 
fore part of the external surface of the inner condyle. 

The cancellous tissue at the upper end of the femur is arranged in a system 
of " pressure lamellae " and " tension lamellse : " the former spring from the 
inner side of the neck and ascend to the head and to the great trochanter ; 
these are crossed at right angles by the tension lamellse, which start from the 
outer side of the shaft and pass upward ami inward. The concave side of 
the neck is further strengthened by a vertical plate of compact tissue, the 
calcar femorale, just in front of the small trochanter. 

The average length of the adult European femur is 18 inches for the male 
and 17 inches for the female ; is .275 of the stature, and its proportion to the 
humerus is 100 : 71. The inclination of the femur is 9° with the sagittal plane 
(the two bones approach each other below) and 5° with the frontal ; it is also 
twisted in a direction opposite to that of the humerus. 



THE LEG. 83 

The angle of the neck with the shaft is open in the foetus and child, then 
Lessens andei the weight of the body, but undergoes no change after growth 

is completed. The upper part of the gluteal ridge may form ;i third trochanter, 
always present in the horse. 

In place of or in addition to the ridge there may be a fossa In/pot rochanterica. 
A marked development of the linea aspera gives a, pilastered femur. The ad- 
ductor tubercle may he of large size. 

The femur is developed from one primary centre and four epiphyses ; more 
of growth in length depends upon the lower epiphysis, as it unites last. 

Describe the patella. 

The patella, or knee-pan, is a sesamoid bone developed in the tendon 
of the quadriceps extensor cruris. It is somewhat triangular, with its 
apex below. Its anterior surface is convex and striated and pierced by 
vascular foramina. The superior border is broad and sloped from behind 
downward and forward, and gives attachment to the rectus and crureus 
portions of the quadriceps extensor. 

The posterior surface of the bone presents two vertical and two trans- 
verse ridges : one vertical ridge is close to the inner margin ; the other is 
distinct and divides the surface into two parts, the external of which is 
the larger and transversely concave, the inner smaller portion is convex. 

The faint transverse ridges divide the articular surface into an upper 
two-sixths, a middle three-sixths, and a lower one-sixth. In usual ex- 
tension the lower one-sixth is in contact with the femur, in mid-flexion 
the middle three-sixths, and in extreme flexion the upper two-sixths ; also 
in extreme flexion the thin marginal facet is the part in contact with the 
inner condyle. Below the articular surface is a rough triangular area ; 
the ligamentum patellae springs from the apex. 

In the third month there is a deposit of cartilage in the quadriceps tendon ; 
ossification begins from one centre in the third year and is completed at 
puberty. 

THE LEG. 
Describe the tibia. 

The tibia (flute), or shin-bone, is the inner and anterior of the two 
bones of the leg, and transmits the weight of the trunk to the foot. It 
articulates with the femur, fibula, and astragalus ; has a shaft and two 
extremities. 

The superior extremity, or head, is thick and broad transversely. It 
forms on each side a tuberosity, on the upper aspect of which is a con- 
cave articular surface for the condyles of the femur. The internal tuber- 
osity is larger than the external, and marked posteriorly by a horizontal 
groove for the semimembranosus. The external tuberosity at the junc- 
tion of the anterior and outer surfaces forms a prominent tubercle for 
the insertion of the ilio-tibial band ; below this are often attached a few 
fibres of the extensor longus digitorum and of the biceps. At the pos- 
terior and under part is a flat articular surface for the fibula, looking 
down, out, and back. The internal condylar surface is oval, more hoi- 



84 BONES OF THE LOWER EXTREMITY. 

lowed than the external, and longer ; the external is nearly circular, con- 
cave from side to side, and more or less convex from before backward ; 
it is prolonged a little posteriorly where the popliteus glides. The 
periphery of each articular surface is flattened for the semilunar fibro- 
cartilage. 

Between the condylar parts is an interval depressed in front and behind 
for attachment of crucial ligaments, and elevated in the middle, forming 
the .spine, the summit of which presents two compressed tubercles with 
an intervening hollow. The depression behind the spine is continued 
into the popliteal notch, which separates the tuberosities posteriorly. 
Anteriorly, at the junction of the head and shaft, is the tubercle or ante- 
rior tuberosity for attachment of the ligamentum patellae. 

The shaft is three-sided, diminishing in size as it descends for about 
two-thirds of its length, and then increasing again. The internal surface 
is convex and nearly subcutaneous. _ At the inner side of the tubercle 
are the insertions of the gracilis, semitendinosus, and double insertion of 
the sartorius. The anterior border runs sinuously from the tubercle to 
the front of the inner malleolus : its upper two-thirds is the crest of 
the tibia, its lower third is smooth. The external surface is hollowed in 
its upper two-thirds, where it lodges the tibialis anticus ; below this the 
surface turns forward and is covered by the extensor tendons. The 
upper third of the posterior surface is crossed obliquely by the popliteal 
or oblique line, running down and inward: it gives origin to the soleus. 
Above it is a triangular area occupied by the popliteus; below it, in 
the middle third of the shaft, is a longitudinal ridge marking off two 
portions, an inner for the flexor long. dig. , and an outer for the tibialis 
posticus. Below the oblique line a large medullary canal runs down- 
ward. The posterior surface is separated from the internal by the inter- 
nal border, which is most distinct in the middle third, from the external 
surface by the external border or interosseous ridge. 

The inferior extremity is broad from side to side, and projects down- 
ward internally to form the inner malleolus. This malleolus is marked 
posteriorly by a groove for the tibialis posticus tendon, and more exter- 
nally by a depression for the flex. long. poll. The external surface of 
the extremity is hollowed for the fibula, and rough for ligaments except 
along the lower border. Below is an articular surface, quadrilateral, 
concave, narrower behind than in front. It shows a slight median ele- 
vation separating two lateral depressions. Internally the cartilaginous 
surface is continued upon the inner malleolus. 

The ratio of the length of the femur to that of the tibia is 100: 81 in the 
European, or 100 : 86 in the Bushman. The tibia is twisted with an angle of 
torsion of 5° to 20°. The shaft may be much compressed laterally, so that 
the skin and posterior longitudinal ridge are very prominent ; such bone is 
platycnemic. 

A facet at the anterior margin of the inferior extremity for articulation 
with the neck of the astragalus is rare in Europeans, but common in lower 
races of men. 



THE LEG. 85 

The tibia is developed from throe centres: the secondary one for the upper 
extremity usually appears before birth. The tubercle may have a separate 
centre. 



Describe the fibula. 

The fibula (clasp), or peroneal bone, nearly equals the tibia in length ; 
its purpose in the leg is mainly for elasticity. Its shaft is convex back- 
ward, and its lower extremity is placed a little in advance of the upper. 
The upper extremity, or head, is prolonged upward at its back part 
into the styloid process ; inside this is a facet looking upward, inward, 
and forward for articulation with the tibia ; more externally is a slight 
excavation for the -biceps; the peroneus longus is attached in front and 
soleus behind. A somewhat constricted part below the head is the neck. 
The lower extremity, or external malleolus, is pyramidal and longer than 
the internal malleolus ; internally it shows a triangular, smooth, articular 
surface for the astragalus, and behind this a depression for the posterior 
band of the external lateral ligament. 

Posteriorly is a shallow groove for the peroneus longus and brevis 
tendons. Externally this extremity is convex and subcutaneous. 

The shaft presents four surfaces — anterior, posterior, internal, and 
external; and four borders — antero-external, antero-internal, postero- 
external, and postero-internal (Gray). 

The antero-external border begins in front of the head and bifurcates 
below to embrace the triangular subcutaneous surface of the external 
malleolus: this border is between the peroneal and extensor muscles. 
The antero-internal border, or interosseous ridge, is close to the pre- 
ceding and parallel with it in the upper third. It terminates below at 
the apex of a rough surface just above the articular facet, The attached 
interosseous membrane separates the extensors in front from the tibialis 
posticus behind. 

The poster.o-external border commences at the base of the styloid pro- 
cess and terminates below in the posterior border of the external mal- 
leolus. It is directed out above, then back, then slightly inward below. 
It separates the peronei from the flexor muscles. The postero-internal 
border, or oblique line, commences inside the head, and ends by joining 
the interosseous ridge in the lower fourth of the bone. 

The anterior surface is very narrow above, broader and grooved 
below; to it is attached the extensor prop, poll., the extensor long, 
dig., and peroneus tertius. 

The external surface is directed outward above and backward below, 
and is occupied by the peroneus brevis and longus muscles. 

The interned surface between the antero-internal and postero-internal 
borders is grooved for the tibialis posticus. 

The posterior surface looks backward above and directly inward be- 
low. Its upper third attaches the soleus muscle ; its lower part is rough 
for interosseous ligaments ; to the rest of the surface is attached the 



86 BONES OF THE LOWER EXTREMITY. 

flexor long. poll. The medullary canal opens on this surface and is 
directed downward. 

The fibula is developed from three centres: the centre for the lower epiph- 
ysis appears first and unites first, contrary to the general rule: sometimes 
the medullary canal runs toward the knee. The fibula in the embryo is nearly 
a-; large as the tibia, is not twisted, and articulates with the femur. The 
tibial malleolus at first is larger than the fibular ; the prominence of the latter 
is acquired after birth. 

THE FOOT. 
Name the bones constituting the tarsus. 

The tarsus is composed of seven bones — the calcaneum or os calcis, and 
the astragalus, forming the hind-foot, the navicular 'or scaphoid, three 
cuneiform, and cuboid, forming the fore-foot. 

Describe the os calcis. 

The os calcis (heel) is the largest bone of the foot : it articulates with 
the astragalus above and cuboid in front ; its principal axis runs down- 
ward and forward. The bone presents six surfaces. The posterior ex- 
tremity, or tuberosity, presents inferiorly two tubercles: the inner is the 
larger. Its posterior surface presents three districts — a smooth one for 
a bursa, a ligamentous one for the tendo Achillis, and a lower convex 
part for the pad of the heel. The part in front of the tuberosity forms 
a slightly constricted neck. 

The internal surface is deeply concave, and surmounted above by the 
sustentaculum tali (support of the astragalus) : this projects inward on a 
level with the upper surface, and is grooved beneath for the flexor long, 
poll. The superior surface has two articular fleets, separated by a groove 
which runs forward and outward for the interosseous ligament, The an- 
terior facet, often subdivided into two, is on the sustentaculum, and is 
concave longitudinally ; the other one is convex. At the fore part of 
the groove is a roughness for the extensor brevis digit. . Behind the 
articular surfaces is a region convex from side to side and concave from 
before backward : above it is placed adipose tissue in front of the tendo 
Achillis. 

The anterior surface is concavo-convex for articulation with the cuboid. 
The inferior surface, in front of the tuberosity, projects in an anterior 
tubercle with a transverse groove in front, and gives attachment to an 
inferior calcaneo-cuboid ligament. 

The external surface is usually flat, and presents near the centre a 
tubercle for the middle fasciculus of the external lateral ligament, and 
anteriorly often a peroneal spine, separating two grooves — the upper for 
the peroneus brevis tendon, the lower for that of the peroneus longus. 

Describe the astragalus. 

The astragalus (a die), or talus, receives the weight of the body from 
the leg. It articulates with four bones— the tibia above and internally, 



THE FOOT. 87 

the fibula externally, os calcia below, and scaphoid in front Its long 

axis is forward and inward. The main part is the body, the convex an- 
terior portion the head, just behind which is the necJc. The superior 
articular surface occupies the whole of the upper surface of the body 
and sends a prolongation down on either side. The trochlear part is 
convex and slightly concave from side to side, wider in front than 
behind ; its outer margin is longer than the inner, and curved, while 
the inner is straight. The inner lateral part is sickle-shaped for the 
internal malleolus ; the outer lateral part is concave and triangular and 
articulates with the external malleolus. Inferiorly there are two articular 
surfaces for the calcaneum : the posterior one is concave, separated by 
the interosseous groove from the anterior one, -which is convex. The 
head articulates anteriorly with the scaphoid : at the lower and inner 
part, between this and the anterior articulation for the os calcis, is a 
facet resting upon the inferior calcaneo-scaphoid ligament, the three 
forming one continuous surface. The posterior surface is small and nar- 
row, and marked by a groove for the flexor long. poll. Bounding the 
groove are two tubercles, the external more prominent and giving attach- 
ment to the posterior band of the ext. lat. ligament. 

Describe the scaphoid bone. 

The scaphoid, or navicular bone, is placed between the astragalus and 
cuneiform bones. It is long transversely, and presents posteriorly an 
articular cavity for the head of the astragalus, and anteriorly a convex 
surface divided into three facets. The superior surface is convex and 
rough for ligaments ; the lower is narrower and irregular. At the outer 
end may be a facet for articulation with the cuboid. The inner end 
forms a prominent tuberosity, directed downward for insertion of the 
tibialis posticus tendon. It articulates with the astragalus, three cunei- 
form, and sometimes the cuboid. 

Describe the cuneiform bones. 

The cuneiform (wedge-shaped) bones are called first, second, and third 
from within out, or the internal, middle, and external : they are placed 
between the scaphoid and inner three metatarsals ; the internal is the 
largest, the middle the smallest. 

The internal cuneiform has its sharp border directed up, and its thick 
rounded base projects downward. The anterior articular surface for the 
first metatarsal is larger than the posterior, is kidney-shaped, and is con- 
vex. The internal surface is free and uneven, and marked by an oblique 
groove ending in an oval facet for the tendon of the tibialis anticus. 
On the outer surface, along the superior and posterior borders, is an 
L-shaped facet for the middle cuneiform, and anteriorly a facet for the 
second metatarsal. Articulates with four bones — scaphoid, middle cunei- 
form, first and second metatarsal. 

The middle cuneiform has its base directed upward and sharp edge 



88 BONES OF THE LOWER EXTREMITY. 

downward : the anterior end is narrower than the posterior, and articu- 
lates with the second metatarsal. On the inner side is an L- shaped facet 
for the internal cuneiform, and on the outer side posteriorly a facet for 
the external cuneiform. Articulates with four bones — scaphoid, internal 
and external cuneiform, and second metatarsal. 

The external cuneiform has its base upward. Its anterior end is trian- 
gular for the third metatarsal, and continuous with it are small lateral 
facets for the second and fourth metatarsal. On the posterior part of 
the inner surface is a facet for the middle cuneiform, and on the outer 
surface a larger one for the cuboid. Articulates with six bones — scaphoid, 
middle cuneiform, cuboid, second, third, and fourth metatarsal. 

Describe the cuboid bone. 

The cuboid is on the outer side of the foot between the calcaneum and 
fourth and fifth metatarsals. It is pyramidal rather than cuboid by the 
sloping of four surfaces to the short external border. If the base of the 
bone were external, the lateral thrust of the cuneiforms would throw it 
out of the arch. 

Posteriorly it articulates with the os calcis by a concavo-convex sur- 
face, and its lower internal corner projects back beneath that bone. 

The anterior surface, smaller than the posterior, shows an internal 
quadrilateral and an external triangular facet for the fourth and fifth 
metatarsals. In the middle of its internal surface is a facet for the ex- 
ternal cuneiform, and behind this often a smaller one for the scaphoid. 
The superior surface is rough for ligaments. On the inferior surface is 
a thick ridge or tuberosity, at the outer end of which is a smooth facet 
where the peroneus longus tendon turns into the sole : in front of the 
tuberosity is a groove for the tendon, and behind it a depression for the 
calcaneo-cuboid ligament. Articulates with four bones — os calcis, exter- 
nal cuneiform, fourth and fifth metatarsal, and sometimes with the 
scaphoid. 

A reduction in the number of tarsal bones may occur from a congenital 
synostosis of the os calcis and scaphoid, os calcis and astragalus, or astragalus 
and scaphoid. An increase may arise from the separation of the external 
tubercle at the back of the astragalus (os trigonum), a separation of the tuber- 
osity of the scaphoid, or a division of the internal cuneiform into two pieces: 
a supernumerary ossicle may occur at the front of the os calcis or at the front 
of the internal cuneiform. 

Describe the metatarsus. 

The five metatarsals resemble the metacarpals ; are slightly convex on 
the dorsum, are three-sided, and have rounded heads. The first is 
short, thick, and massive : on the base is a large kidney-shaped facet for 
the internal cuneiform, sometimes a lateral facet on the outer side for 
the second metatarsal. The lower part of the base forms the tuberosity, 
projecting down and out and presenting an impression for the peroneus 
longus. On the inner side is a small mark for the tibialis anticus. The 



THE FOOT. 85» 

superior surface of the shaft looks inward : the inferior is concave, the 
external triangular and flat. The head is large, and shows interiorly a 
median ridge separating two grooves in which the sesamoid bones glide. 
The remaining four bones are distinguished from the metacarpals by 
being more slender and compressed, corresponding to a form of foot 
narrower than that of the hand. Their heads are elongated from above 
down, and end below in two small projections. On each side are a tubercle 
and depression for the lateral ligament. Their bases furnish distinctions. 
The second has a triangular base articulating with the middle cuneiform : 
on its inner side is a small facet for the internal cuneiform, and some- 
times a small one for the first metatarsal. On the outer side is an upper 
and lower facet, each subdivided into two. making four : the two poste- 
rior articulate with the external cuneiform, the two anterior with the 
third metatarsal. The third has a triangular base for the external cunei- 
form : on the inner side are two facets for the second, and on the outer 
side a single one for the fourth. The fourth has an oval or quadrangular 
base for the cuboid : on the inner side is usually a double facet for the 
third metatarsal and external cuneiform, and on the outer side a single 
one for the fifth. The fifth articulates internally with the fourth, and 
behind by an obliquely cut surface with the cuboid : it projects exter- 
nally into a large tuberosity into which the peroneus brevis is inserted. 
An independent ossicle may take the place of this tuberosity. 

Two sesamoid bones lie side by side in the plantar wall of the first 
metatarso-phalangeal joint. There may be small ones for the other toes. 

Describe the phalanges. 

The phalanges of the toes correspond closely to those of the fingers. 
Those of the four outer toes are smaller than those of the hand, but 
those of the great toe are larger than those of the thumb. The shafts 
of the first row are compressed laterally ; those of the second row, espe- 
cially in the fourth and fifth toes, are hardly longer than their breadth. 
The last two phalanges of the little toe may be ankylosed (36 per cent. ) 
as frequently in the infant as in the adult. 

Ancient art represents the second toe as longer than the great toe. This 
may have been copied from some lower race, but in the present white races 
the great toe is longer in nearly all cases. 

Describe the bones of the foot as a whole. 

The foot is narrowest at the heel, and broadens as far as the meta- 
tarsal bones. The astragalus overhanging the sustentaculum tali inclines 
inward so much that its external border is over the middle line of the os 
calcis. The foot is arched longitudinally from the heel to the heads of 
the metatarsals— a double arch in front and a common support behind. 
The internal division of the arch is most raised, and consists of the pos- 
terior two-thirds of the calcaneum, the scaphoid, cuneiform, and three 



90 BONES OF THE LOWER EXTREMITY. 

inner metatarsals; the outer arch consists of the whole length of the cal- 
caneum, the cuboid, the fourth and fifth metatarsals. There is also a 
transverse arch formed by the cuboid and three cuneiform, and in front 
by the metatarsals. 

In the infant the head of the astragalus is directed more inward than in 
the adult, and the foot is inverted. The first metacarpal is also short and 
inclined inward, the young foot resembling that of an ape. 

The tarsal bones are all ossified in cartilage from a single nucleus, except- 
ing the os calcis, which has an epiphysis on the posterior extremity. The 
metatarsals and phalanges agree with the corresponding bones of the hand, 
each from a principal centre, and one secondary one : the four outer meta- 
tarsals have the epiphysis at the distal extremity ; in the metatarsal of the 
great toe and in the phalanges the epiphyses are at the proximal ends. 

What are some of the homological comparisons of the upper and 
lower limbs? 

The peripheral parts of both limbs in man and animals show a quinquefid 
division, but certain vestiges of suppressed digits give reasons for believing 
that this division was preceded by one of seven (heptadactyle). The nerves 
entering into the limb plexuses are in each case seven (crural plexus being 
composed of the lumbar and sacral). 

The thoracic and pelvic limbs are constructed on the same general type, 
modified according to use — e. g. in the upper limb of man the free motion of 
the shoulder-joint, the eversion of the humerus, the forward flexion of the 
elbow, the pronation and supination of the hand, the opposability of the 
thumb, all show this to be an organ of prehension and touch and subservient 
to the head; in the lower limb the fixed condition of the pelvic girdle, the 
greater strength of bones, the close-fitting hip-joint, the backward flexion of 
the knee, and non-opposability of the great toe, all have relation to stability, 
locomotion, and support of weight. 

Figs. 4 and 5 show the junctions of the limb-stalks to the trunk : the bones 
of the trunk are black, those of the girdles shaded. The shoulder girdle is 
imperfect in front, and completed by the sternum ; it is wholly incomplete 
behind. The pelvic girdle is perfect in front, and is completed behind by the 

Fig. 4. 




^lllte 



Shoulder Girdle (Henle). 



sacrum, giving solidity in mai-ked contrast to the mobility of the upper girdle. 
The dorsal portions of the girdles are the scapula and ilium : the ventral por- 
tion is in each case double, including the clavicle and coracoid above, the 



THE FOOT. 91 

pubis and ischium below. The coracoid ;ui<l ischium correspond : the clavicle, 
may correspond to the reptilian precoracoid, which represents the pubis. The 

subscapular fossa represents the gluteal surface of the ilium, as the scapula 
has been rotated out and the ilium inward, in accordance with the rotation 
of the free parts of the limbs. 

In the earliest stage the limbs hud out and have a dorsal and ventral aspect : 
in the next stage, when they come to be folded against the body, one border 
will look toward the head (preaxial) and one toward the tail (postaxial). Thus 

Fig. 5. 

,,*< «» I "* B «* X 

/ Y 
_ piiii) 




Pelvic Girdle (Henle). 

the great tuberosity of the humerus, its radial condyle, the radius, and thumb, 
the small trochanter of the femur, its internal condyle, the tibia, and great 
toe, are preaxial. In higher animals and man further changes occur accord- 
ing to function. The humerus in man is rotated out about 45°, so that its 
radial condyle becomes external ; the femur is rotated in about 90°, bringing 
the tibial condyle to the inner side. 

The pisiform of the carpus has been considered a sesamoid bone in the ten- 
don of the flexor carp, uln.: it may be the representative of a suppressed 
digit. The tuberosity of the scaphoid of the carpus and of the navicular of 
the tarsus correspond, and may each represent a suppressed digit. 

Table of Homologous Bones in Thoracic and Pelvic Limbs. 
Thoracic Limb. Pelvic Limb. 
Scapula Ilium. 

Precoracoid Pubis. 

Coracoid Ischium. 

Glenoid cavity Cotyloid cavity. 

Clavicle Absent. 

Humerus Femur. 

Great tuberosity Small trochanter. 

Small tuberosity Great trochanter. 

External condyle and capitellum . . . Internal condyle. 

Internal condyle and trochlea External condyle. 

Absent Patella. 

Radius Tibia. 

Ulna Fibula. 

Carpus Tarsus. 

Metacarpus Metatarsus. 

Pollex Hallex. 

Digital phalanges Digital plu 



92 BONES OF THE LOWER EXTREMITY. 

Homologies of Carpus and Tarsus. 

Carpus. Tarsus. 

Pyramidal) Os calcis. 

Pisiform j 

£ un ** 1 Astragalus. 

Scaphoid j 

Tuberosity of scaphoid j Navicular. 

Os centrale ) 

Trapezium Internal cuneiform. 

Trapezoid Middle cuneiform. 

Os magnum External cuneiform. 

Unciform Cuboid. 

Comparisons of Stability in Hand and Foot. 

.Stability. Intermediate Mobility. 

{carpus 2 
metacarpus 3 
phalanges 5 

i tarsus 5 
metatarsus 3 
phalanges 2 

Homologous Parts of Scapula and Ilium. 
Scapula. Ilium. 

Supraspinous fossa Sacral surface. 

Infraspinous fossa Iliac fossa. 

Subscapular fossa ....... Gluteal surface. 

Spine and acromion Ilio-pectineal line. 

Superior border Posterior border. 

Axillary or glenoid border . . . Anterior or cotyloid border. 
Base (vertebral border) .... Iliac crest. 

Superior angle Posterior superior spine. 

Inferior angle Anterior superior spine. 

What facts show the adaptation of the skeleton to the erect 
attitude ? 

For maintaining this position the muscles passing over the ankle-joint 
must constantly act : at the knee- and hip-joints the ligaments are more con- 
cerned. A vertical plane through the vertex of the skull passes through the 
occipito-atlantoid, lumbo-sacral, sacro-iliac, hip-, knee-, and ankle-joints. In' 
the infant the size of the head amounts to nearly one-fifth of the body, and 
the middle distance between the vertex aud sole of the foot is above the um- 
bilicus; in the adult a similar point is near the symphysis pubis. The skull 
is nearly balanced, and the plane of the foramen magnum is nearly horizon- 
tal. The face and orbits look forward, the nostrils down. The spinal column 
is pyramidal and fitted to sustain weight. The thorax is compressed antero- 
posteriorly, carrying the centre of gravity backward near the spine. The 
iliac portion of the pelvis supports the abdominal viscera. The femur is 
longer than tbe tibia, to give sufficient extent of stride aud powers of bal- 
ancing. The upper limb is adjusted for mobility, and not for support. The 



ARTHROLOGY. 03 

foot of man alone among animals has an arched instep. The great toe is con- 
stituted not for grasping, but for support. 



ARTHROLOGY. 

What are the structures forming joints ? 

Bones, cartilage, ligaments, and synovial membrane enter into the 
formation of joints. 

The articular portions of bones are enlarged to form a joint of suitable 
size, and so that muscles passing over the joint can act at a greater angle. 
The layer of bone beneath the cartilage is a compact articular lamella. 
The cartilage is usually hyaline, may be fibro-cartilage or yellow elastic. 

The ligaments are mainly white fibrous tissue ; some are yellow elastic. 

The synovial membrane is like a short wide tube covering the inner 
surface of the ligaments; its secretion is synovia," 95 per cent, water, 3.51 
per cent, albumin and salts. There are three kinds of synovial mem- 
brane — articular, bursal, and vaginal. The former in the foetus is said 
to cover the articular cartilages as well as ligaments. 

The bursa' are mucous as between integument and bone, and synovial 
between muscles or tendons and bone. 

Vaginal synovial membranes are sheaths for tendons. 

What is the classification of joints? 

Gray classifies them as synarthrodia!, immovable ; amphiarthrodial, 
mixed ; and diarthrodial, or movable. 

vera f dentata — e. g. interparietal. 
f ( true ) \ serrata— e. g. interfrontal. 
^Sutura I [hmbosa— e. g. fronto-parietal. 

Synarthrodia^ J I "f}\ { squamosa-,, g. squamo-parietal. 

immovable ' a ■ I. (ialse) ( harmonia—f. <9 . intermaxillary. 

| Schindylesis — e. g. rostrum of sphenoid and vomer. 
[ Gomphosis — e. g. tooth in alveolus. 
j ( 1 ) Surfaces connected by fibro-cartilage, not separated by 
Amphiarthro- J synovial membrane — e. g. bodies of vertebrae, 

dial, mixed | (2) Surfaces covered by fibro-cartilage and partially lined 
^ by synovial membrane — e. g. pubic symphysis. 
Arthrodia gliding (not referable to any axis)— e. g. some 

movements in temporo-maxillary articulation. 
Eimrthrosis, ball-and-socket — e. g. shoulder and hip. 
Ginglymus, hinge — e. g. elbow, knee; no lateral motion. 
movable 1 ' \ ^ art ^ r0SIS rotatoria, or lateral ginglymus, a pivot within 
a ring — e. g. atlo-axoid. 
Condyloid, ovoid head in elliptical cavity — e. g. wrist. 
Reciprocal reception, saddle-shaped — e. g. carpo-meta- 
carpal joint of thumb. 



Diarthrodial. 



94 

What agents keep joint surfaces together ? 

1. Atmospheric pressure — e. g. hip-joint; 2. synovial fluid; 3. liga- 
ments to a small extent ; 4. muscles, important. A short muscle may 
act on more than one joint ; gluteus maximus extends the hip and also 
the knee through the rectus femoris. 

What limits motion in joints ? 

1. Extent of articular surfaces ; 2. bony contact; 3. approximation of 
soft parts ; 4. manner of articulation ; 5. anatomical separation of joint 
into two, as the joints of a vertebra. 

HENLE'S CLASSIFICATION OF JOINTS. 

I. Synarthrodia; II. Diarthrodia. 

I. Synarthrodia— a firm joint; characteristics are (1) junction along entire 
extent of adjacent surfaces by a third tissue ; (2) motion is due to the gliding 
of this tissue; (3) bones d<3 not touch. 

(a) Synchondrosis, where intervening tissue is remains of embryonal tissue, 
not hyaline, but fibrous or elastic — e. g. (1) petrous bone and jugular process ; 

(2) sacro-iliac and intervertebral articulations : (3) the band may ossify, synos- 
tosis — e. g. sphenoid and occipital or interfrontal suture; (4) small space hol- 
lowed out, so intervening cartilage is incomplete ; hemiarthrosis, or false syn- 
chondrosis. 

(6) Syndesmosis, a suture. Fibrous or membranous tissue intervenes and 
motion is practically nil ; not an interlocking, as connective tissue is inter- 
posed, but the union is strengthened by serrations. 

II. Diarthrodia, movable. In development two segments of bone will en- 
croach upon a middle portion, so that the opposite articular surfaces come in 
contact. The enveloping perichondrium becomes periosteum, and ultimately 
capsular ligament. At the periphery of a concave surface may be developed 
a fibro-cartilagiuous ring or glenoid ligament. 

The capsule extends only to the hyaline cartilage, tough externally and 
differentiated internally into synovial membrane. 

There may be only a partial deliquescence of blastema, and two articular 
cavities are formed with interarticular fibro-cartilage. Next the bones may 
be in actual contact by a liquefaction in part of the intervening substance, 
forming hemiarthrodia : the pubic symphysis is usually synarthrodia!, but in 
pregnancy there may be a slight liquefaction, forming an hemiarthrodial 
joint. A continued liquefaction produces a diarthrodia! joint, characterized 
by (1) direct touch of opposed surfaces; (2) bones covered by articular carti- 
lage; (3) joint enclosed in a capsule. There is no proper synovial sac: a 
change occurs on the inner surface of the cartilage and capsule to small flat 
cells ; the synovial fluid fills up irregularities and makes better coaptation. 
Liquefaction may occur in such a way as to produce a vertical layer, as the 
crucial ligaments. 

To classify special joints various principles of subdivision may be em- 
ployed: (1) coaptation of the bones forming joints ; (2) extent of surfaces; 

(3) shape of surfaces. There are no special names given to the first variety : 
joints with non-coaptated surfaces are very numerous ; the spaces are filled 
with interarticular cartilages or synovial folds. The cartilage may remain 
fixed or it may move on the joint-socket, and the head of a bone move on 
the cartilage — a sort of double joint, as at the temporo-maxillary and knee- 



AKTICl'LATIONS OF THE TRUNK AND BEAD. 05 

joints. Almost always the curve of the joint-head is of smaller radius than 
that of the joint-socket. 

Joints named from the extent of articular surfaces are ampkiarthrodial 
(arthrodia or gliding of Gray); characteristics are (1) surfaces piano or 
nearly so; (2) extent of surface the same; (3) firm, dense capsule; (4) motion 
slight : typical examples are petro-occipital and ilio-sacral. Joints may some- 
tinus change from one variety to another by absorption or change in the in- 
terarticular tissue. 

Joints named according to shape of articular surfaces are — (1) with spherical 
surfaces, ball-and-socket, arthrodial (enarthrosis, Gray) ; (2) with elliptical sur- 
faces, condylarthrosis, as radio-carpal; (3) with saddle-shaped surfaces, carpal 
joint of thumb: (4) with cylindrical surfaces : (a) hinge-joint, ginglymus, pro- 
duced by a cylindrical surface at right angles to the shaft ; the cylinder may 
be grooved or ridged antero-posteriorly ; (6) screw-like joint, as at elbow, where 
central ridge is not antero-posterior, but if continued would form the thread 
of a screw; (c) rotation-joint, trochoides (lateral ginglymus of Gray), cylinder 
parallel to shaft. (5) Mixed or ginglymo-arthrodial, metacarpophalangeal : lat- 
eral ligaments control movement in certain directions. 

The motions possible in joints are (1) radial, as flexron and extension; (2) 
rotatory; (3) circumduction ; (4) gliding. 

Flexion lessens the angles of bones, extension increases that angle. All liga- 
ments besides the capsular and those within the capsule are called accessory : 
strengthening bands of the capsule, and separated from it by a layer of con- 
nective tissue, are regarded as accessory ligaments. 

ARTICULATIONS OF THE TRUNK AND HEAD. 
What are the articulations of the trunk and head ? 



1 . Of the vertebral column. 

2. Of the false vertebrae. 

3. Of rotation vertebrae with 
each other and with occiput : 

(a) atlas with axis; 

(b) occiput with atlas ; 

(c) occiput with axis. 



4. Of ribs with vertebrae. 

5. Of costal cartilages with ster- 
num and with each other. 

6. Of sternum. 

7. Of hyoid bone. 

8. Of skull. 

9. Of lower jaw. 



Articulations of the vertebral column comprise five sets: (1) those 
between the bodies of the vertebrae; (2) between the laminae; (3) be- 
tween the articular ; (4) the spinous ; (5) and the transverse processes. 

Describe the ligaments of the bodies. 

Anterior common, posterior common, and intervertebral substance. 
The anterior common extends along the front of the bodies, filling up 
the concavities of the vertebrae from the axis to the sacrum : it is 
broader below than above, and thicker opposite the front of the body, 
where it is loosely connected, than opposite the intervertebral disk, 
where it is closely connected. It consists of several layers of fibres, 
the superficial set extending from a given vertebra to the fourth or fifth 
below it, and a third deep set from one to another. The ligament splits 
for the passage of vessels to the vertebral body. 



96 ARTICULATIONS OF THE TRUNK AND HEAD. 

The posterior common ligament is inside the spinal canal, along the 
posterior surface of the bodies, and extends from the axis to the sacrum. 
It is broader above than below, and laterally presents a series of denta- 
tions over the intervertebral disks, and concavities over the centres of 
the bodies, from which it is separated by the venae basis vertebrae. It 
has denser fibres than the anterior ligament, and is similarly divided into 
sets. 

The intervertebral substances are disks of fibro-cartilage placed be- 
tween the bodies of the vertebrae from the axis to the sacrum. They 
vary in size and thickness in the different regions, being thicker behind 
than in front in the lumbar and cervical regions, and uniformly thick in 
the dorsal region. They form about one-fourth of the spinal column or 
one-third of the lumbar region, one-fourth of the cervical, and one-fifth 
of the dorsal. They are connected with the anterior and posterior com- 
mon ligaments, and in the dorsal region with the heads of ribs. They 
are composed at the circumference of laminae T ^o to ^j inch (] to \ mm.) 
broad, of fibrous and fibro-elastic tissue and fibro-cartilage arranged con- 
centrically one within the other, and surrounding in the centre a soft, pulpy 
mass. The laminae are not composed of different materials, but owe their 
difference in appearance to the fact that they are obliquely placed, cross- 
ing each other like an X, and the light strikes them differently : some fibres 
run horizontally. The most external fibres resemble those of a tendon. 

The central part is pulpy, soft, and yellow, containing cells in a fibrous 
matrix : it rises up conically when pressure is removed. The interver- 
tebral disks are compressible, and, according to one set of measurements, 
a man is \ inch taller in the morning than at night. 

Describe the ligaments of the laminae and processes. 

Those connecting the laminae are the ligameiita subflava, of yellow elastic 
tissue attached to the anterior surface of the lamina above and posterior 
surface and upper margin of the lamina below. They are analogous to 
the intervertebral substances in front. Each ligament consists of two 
lateral portions, which commence on each side of the root of either artic- 
ular process and pass to the convergence of the laminae. They do not 
exist between the occiput and atlas, atlas and axis : they take the place 
of active material and help muscles pull back the flexed column. 

The ligaments of the articular processes are capsular, thin, loose sacs 
attached to their margins and completed internally by the ligamenta sub- 
flava. They are lined by synovial membrane. 

The interspinous ligaments are thin and membranous, extending from 
near the root to the summit of the spinous process. They are slightly 
developed in the neck, narrow in the dorsal region, and thicker in the 
lumbar. 

The supraspinous ligament is a strong cord connecting the apices of 
the processes down from the seventh cervical. Its most superficial fibres 
connect three or four vertebrae and its deepest neighboring vertebrae. 

The Ugamentum uuehee continues the supraspinous ligament upward 



ROTATION VERTEBRAS. 97 

in the neck, and is attached to the external occipital protuberance. In 
the human subject it is only an intermuscular septum between the two 
trapezii. A fibrous slip is given off iroui its anterior surface to each cer- 
vical spinous process. 

The intt rtransvi rse ligaments are scattered fibres in the cervical region, 
rounded cords in the dorsal, and membranous in the lumbar. 

What are the movements of the spinal column ? 

Flexion, extension, lateral movement, circumduction, and rotation — ■ 
all on three axes, one transverse, one antero-posterior, and one vertical. 
Flexion is the freest of all movements : it compresses the disks in front 
and stretches the posterior common ligament and ligamenta subflava. 
Extension is not marked, and is limited by the anterior common liga- 
ment and spinous processes. 

Flexion and extension are most free in the lower lumbar region and 
least in the upper dorsal : extension is greater in the neck than flexion. 
Lateral movement is most free in the cervical and lumbar regions, lim- 
ited by the approximation of transverse processes. Circumduction is 
limited. Rotation is free in the upper dorsal and absent in the lumbar 
region. So the cervical region enjoys the greatest extent of each variety : 
the dorsal has greatest rotation, while the lumbar has none. We can turn 
the head and trunk through 180° on either side, head and neck through 
79° — three-fifths of it is between atlas and axis ; back and loins through 
28° ; and in joints below this through 73°. 

The movements are due largely to the shape of the disks, which limit 
the extent of motion, but not the direction ; it is proportional to their 
height and inversely as their area. 

The vertebral articulations are supplied by the spinal^ nerves in each 
region : by the vertebral and ascending cervical arteries in the neck, the 
intercostal and lumbar below. 

What are the ligaments of the false vertebrae ? 

The lig. sacro-coccygeum articulare connects the cornua of the sacrum 
and coccyx. The lig. sacro-coccygeum ant. is the analogue of the ante- 
rior vertebral. The lateral sacro-coccygeal ligaments correspond to the 
anterior costo-transverse, passing from the lateral edge of the sacrum to 
that of the cocc3 T x. The deep posterior sacro-coccygeal ligament corre- 
sponds to the posterior common, and receives strengthening bands from 
the dura mater of the cord. The superficial sacro-coccygeal closes in the 
lower opening of the spinal canal, passing from the arch of the last sacral 
to the periosteum of the coccyx. This ligament may split below, leaving 
a median cleft. 

Describe the articulations of the rotation vertebrae. 

The ligaments connecting the atlas and axis are two anterior atlo-axoid, 
the posterior atlo-axoid, transverse, and two capsular. The two anterior 
7— A. 



98 



ARTICULATIONS OF THE TRUNK AND HEAD. 



Fig. 6. 



atlo-axoid (anterior obturator) comprise a superficial rounded cord in the 
median line, a continuation up of the anterior common ligament to the 
occiput, and a deeper portion on either side from the anterior arch of 
the atlas to the base of the odontoid and front of the body of the axis. 
In front of them are the recti cap. ant. maj. muscles. 

The posterior atlo-axoid (posterior obturator) ligament is broad and 
thin, connecting the posterior arches of the two bones and supplying the 
place of the ligamenta subflava : it contains a little elastic tissue. Behind 
it are the inferior oblique muscles. The transverse or cruciform ligament 
passes across the ring of the atlas behind the odontoid. It holds the 
odontoid in place, but not with such firmness as often described : it is 
broad and firm in the middle, and in it is often developed a cartilaginous 
nodule ; on each side it is attached to the lateral mass of the atlas. A 
small process passes up (superior crus) from its upper border to the basi- 
lar process, and another down (inferior crus) to the root of the odontoid 
posteriorly. 

The capsular ligaments are thin and loose, strongest in front and ex- 
ternally : there is also a capsule for the anterior odonto-atloid articula- 
tion. The synovial membranes are four in number — one for each capsular 
ligament, one for the anterior articular surface of the odontoid, and one 
for its posterior surface, a sort of bursa which may communicate with 

the occipito-atloid joints. This joint 
possesses great mobility, the greater 
part of the rotation of the head oc- 
curring here, and none in the occipito- 
atloid joints. ^ When the bones are 
covered by articular cartilage a sagittal 
section shows a convexity upon a con- 
vexity (Fig. 6). With the head equi- 
poised and eyes to the front the mus- 
cles are at rest and ligaments tense. 
When the head is rotated the point of 
the atlas sinks down off the axis and 
a part projects ; otherwise an already 
tense ligament would become more 
tense in rotation, did not the points of 
attachment approach each other. 

The spinal column is connected to 
the cranium by ligaments from the 
occiput to the atlas, from the occiput to the axis. 

Describe the articulations of the occiput and atlas. 

There are two anterior occipito-altoid ligaments (anterior obturator), a 
posterior, two lateral, and tivo capsular. 

The superficial anterior occipito-atloid continues the anterior common 
and superficial atlo-axoid ligaments upward to the basilar process. The 
deep ligament is thin, and passes from the anterior margin of the fora- 




OCCIPUT-AXIS, RIBS-VERTEBRAE. 99 

men magnum to the anterior arch of the atlas ; behind it are the odon- 
toid ligaments. 

The posterior occipito-atloid (posterior obturator) is membranous and 
blended with the dura mater of the cord : it passes from the posterior 
margin of the foramen magnum to the posterior arch of the atlas. Lat- 
erally, it is pierced by the vertebral artery and suboccipital nerve. 

The lateral ligaments are fibrous bands passing from the transverse 
processes of the atlas up and in to the jugular processes of the occipital 
bone. The capsular ligaments are loose, and enclose a synovial mem- 
brane, which usually communicates with that between the posterior sur- 
face of the odontoid and transverse ligament. 

The movements in the joint are flexion and extension, a nodding move- 
ment through about 45° : there is a slight lateral motion. 

Describe the ligaments connecting the occiput and axis. 

There are the occipito-axoid and three odontoid. To expose these the 
spinal canal must be opened. The occipito-axoid ligament prolongs the 
posterior common ligament to the front of the foramen magnum, and 
there blends with the dura. This is the broad ligament of the axis (lig. 
lata), and shows three sets of fibres: the posterior blends with the dura, 
the next is the continuation of the posterior common, and the most ante- 
rior or deepest set is confined to the back of the odontoid and body of 
axis : this deepest layer also joins the upper part of the posterior surface 
of the transverse ligament, and is called the superior appendix of the 
transverse ligament. A bursa is often between this broad and the trans- 
verse ligament. 

From either side of the apex of the odontoid process an alar or check 
ligament passes up and out to the inner side of the condyle of the occi- 
put. They limit the extent of rotation. From the apex of the odon- 
toid a middle band passes to the front of the foramen magnum, the 
"suspensory" ligament, but it suspends nothing. 

Should a section be made from behind forward just above the atlas, 
the knife would divide these ligaments in order: the lig. nuchas, the 
posterior occipito-atloid (then the spinal cord), the occipito-axoid, the 
superior crus of the transverse, the odontoid, the deep and superficial 
anterior occipito-atloid. 

Nerves of these joints are from the suboccipital and second cervical ; 
arteiies are from the vertebral. 

Describe the ligaments connecting the ribs with vertebrae. 

There are two sets: (1) connects heads of ribs with bodies; (2) con- 
nects necks and tubercles with transverse processes. 

(1) Anterior costo-vertebral or stellate, capsular, inter articular . The 
stellate consists of three bundles of fibres radiating from the head of the 
rib : the upper bundle passes to the vertebra above, the lower to the 
vertebra below, and the middle to the intervertebral substance. The 
first rib articulates with one vertebra, sends up a slip to the seventh cer- 



100 ARTICULATIONS OF THE TRUNK AND HEAD. 

vical, a middle one to the first dorsal, but not a lower one : there is a 
similar arrangement with the eleventh and twelfth ribs. On the under 
edge of the stellate ligament a deep fasciculus passes from the side of 
the body to the under surface of the head of the rib. 

The stellate ligament is continued into the cervical and lumbar regions : 
a slip from a next higher vertebral body and one from the adjacent in- 
tervertebral disk or body run to the root of the transverse process. 

The capsular ligament is a loose bag, most distinct above and below, 
and firmly connected with the stellate ligament, 

The in'tcrarticidar ligament is a flat horizontal band of fibres passing 
from the intervertebral substance to the crest on the head of the rib : it 
divides the joint into non-communicating cavities, each lined by a sepa- 
rate synovial membrane. The first, eleventh, and twelfth ribs do not 
possess this ligament. 

In many mammals a conjugal ligament unites the heads of opposite 
ribs across the back of an intervertebral disk. 

{2) Articulations of necks and tubercles with the transverse processes 
— superior, middle (interosseous), and posterior costo-transverse ligaments 
and capsular. 

The superior ligaments are two in number : the anterior passes from 
the upper border of the neck of each rib up and out to the lower border 
of the transverse process and neck of rib above. Its inner border com- 
pletes an aperture between it and the articular process, corresponding to 
an anterior sacral foramen. Its external border is continued in a thin 
aponeurosis over the external intercostal muscle. The first rib does not 
possess this ligament. 

The posterior band is less regular, and extends from the neck of the 
rib up and in to the transverse and lower articular process next above. 
< The middle costo-transverse is very short, and connects the neck of the 
rib to the front of the adjacent transverse and articular process. This is 
lacking in the case of the eleventh and twelfth ribs. 

The posterior costo-transverse passes obliquely from the summit of the 
transverse process to the tubercle of the adjacent rib and is accessoryto 
the capsule behind — wanting on the eleventh and twelfth ribs. The joint 
has a thin capsular ligament enclosing a synovial membrane. Nerves 
are anterior branches of spinal nerves, arteries the intercostals. Action 
of these joints is elevation and depression of ribs on a transverse axis 
through the head of a rib and its articular process — i. e. lengthwise 
through its neck : there are also e version and inversion of ribs on an axis 
connecting their sternal and vertebral ends. No movement on a vertical 
axis. 

HENLE'S VERTEBRAL AND COSTAL LIGAMENTS. 

A. Synchondroses and capsular ligaments. Synchondroses are interverte- 
bral substances; capsular are three sets: (1) for articular processes ; (2) for 
beads of ribs; and (3) for tubercles of ribs. 

B. Accessory ligaments — (1) lig. commune vertebr. ant. ; (2) ligg. costo-ver- 
tebralia radiata (stellate). 



COSTAL CARTILAGES ANT) STERNUM. 



101 



c. Ligaments of the intertransverse and posterior parts of the intercostal 




spaces: (a) Ligg. costo-transversaria : (1) antica, (2) postica. The anterior 
costo-transverse is that of Gray; the 

posterior (dp, Fig. 7) has the same 
origin as the anterior; passes up and 

hack and hi furcates, the inner arm 
iroiiiLT to the articular process ahove, 
the lateral arm to the articular and 
transverse process ahove. Posterior 
vt ssels and nerves pass between its 
insertions and beneath its free edge. 
(b) Ligg. colli costse— the lig. colli 
costse sup. aud lig. c. c. inf. form the 
middle costo-transverse of Gray. Lig. 
colli costa 3 posticum passes from the 
neck of rib near the bead through 
the intervertebral foramen into the 
spinal canal to the posterior surface 
of an intervertebral disk : it meets 
its fellow from the other side be- 
neath the posterior common liga- 
ment — lig. costarum jugale of ani- 
mals, (c) Ligg. tuberculi costse, superior and inferior. The inferior one (tci, 
Fig. 7) = the posterior costo-transverse. The lig. t. c. sup. (tcs, Fig. 7) passes 
from the tubercle of one rib to the apex of the transverse process next above. 
(d) Ligg. tuherositatum vertebralium (tv, Fig. 7) = intertransverse of Gray.^ 

The last internal intercostal muscle sends a band from the lower edge of 
the eleventh rib down to the twelfth, often to the twelfth dorsal vertebra ; 
similar fibres go from the twelfth rib to the first lumbar, and from the trans- 
verse process of the first lumbar to the body of the second : it is the acces- 
sory costo-vertebral ligament (stellate), and serves for muscular origin, espe- 
cially of the psoas. 

The anterior costo-transvere ligaments of the lower intercostal spaces and 
two upper lumbar vertebrae unite into a shining aponeurosis, the lumbo-costal 
ligament. It passes transversely from the transverse processes of the two 
upper lumbar vertebrae to the end of the last rib ; thence vertical fibres pass 
down to the ilio-lumbar ligament, usually behind the quadratus lumborum 
muscle. 

D. Ligaments of the spinal canal. (1) Lig. commune verteb. posticum ; (2) 
ligamenta intercruralia = ligamenta subflava. 

E. Ligaments of spinous processes, ligg. interspinalia, lig. supraspinal, 
and lig. nuchse. 

Describe the articulations of the costal cartilages with the ster- 
num. 
Anterior chondro-stemal, posterior chondro-sternal, and capsular. 
The anterior one is a broad, radiating band with superior, middle, and 
inferior fasciculi. They intermingle with those of the opposite side and 
with the origin of the pectoralis major, forming a membrane over the 
sternum, membrana sterni. The posterior chondro-sternal ligaments are 
less distinct, and are composed of radiating fibres blending with the peri- 
osteum. The capsular ligaments are very thin, and connected with the 
anterior and posterior ones. 



102 ARTICULATIONS OF THE TRUNK AND HEAD. 

Synovial membranes, the first, sixth, and seventh cartilages, have 
none ; the third, fourth, and fifth have one ; the second has two and an 
interarticular cartilage resembling a vertebral articulation. In old age 
most of these articulations disappear. 

From the sixth and seventh cartilages chondro-xiphoid (costo-xiphoid) 
ligaments pass down and in to the ensiform, strengthening the sheath of 
the rectus and limiting the aponeurosis of the external oblique. 

Describe the intercostal ligaments. 

There are external and internal intercostal ligaments. The former, 
ligg. intercostalia ext., lie in the nine or ten upper spaces between the 
anterior end of the external intercostal muscle and the sternum. The 
fibres are partly oblique, vertical, and transverse. The vertical and ob- 
lique fibres constitute the lig. corruscans (shining), and seem to be un- 
developed bundles of the external intercostal muscle : they are strongest 
in the third to the seventh spaces. The transverse fibres are present in the 
first to the seventh spaces. 

The internal intercostal lig <ameiUs, ligg. intercostalia int., are tendinous 
fasciculi of the triangularis stern i muscle, passing from rib to rib over 
one or two spaces : in the seventh and eighth spaces, sometimes sixth 
and ninth, they are nearly transverse. 

Describe the interchondral ligaments. 

The cartilages of the sixth, seventh, and eighth ribs, sometimes fifth and 
ninth, articulate by their lower borders with the margins of the adjoin- 
ing cartilage ; each articulation has a capsule and synovial membrane. 
All these articulations may be wanting. 

In articulations of ribs with cartilages the cartilage is held in a de- 
pression in the sternal end of the rib by periosteum. 

Describe the ligaments of the sternum. 

The gladiolus is united to the manubrium by an interposed fibro-car- 
tilage, synarthrodial (Henle), or it may be diarthrodial with a synovial 
membrane in 33 percent, of cases — rarely so in childhood — and probably 
results from absorption. The ligaments are anterior and posterior inter- 
sternal: both consist of longitudinal fibres blending with the chondro- 
sternal ligaments, the anterior with the pectoralis major. 

The ligaments of the hyoid bone will be described with those of the 
temporo-maxillary articulation. 

What are the ligaments of the skull ? 

(1) The petro-occipital synchondrosis possessed originally intervening 
hyaline cartilage, and was a true joint. ( 2) The spheno-occipital synchon- 
drosis contains cartilaginous nodules till ossified at the age of twenty- 
five. The soft masses of connective tissue in the lacerated foramen, the 
petro-occipital and petro-sphenoidal fissures, are known as ligaments of 
the same names. (3) Accessory bands, a number of ligamentous bands 
bridging over grooves and bony points, completing canals : a pterygo-pe- 



TEMPORO-M AXILLARY ARTICULATION. 103 

troscti ligament from the upper part of the posterior border of the ex- 
ternal pterygoid plate to the spine of the sphenoid, sometimes ossified ; 
another bridging over the supraorbital notch ; an intrajugular ligament 
dividing the jugular foramen ; &petro-sphenoidal ligament from the apex 

of the petrous to the posterior clmoid process under which passes the sixth 
nerve. A lack of bone between the foramen ovale and spinosum may 
be supplied by ligament; the clinoid processes of one side may be con- 
nected by ligament ; one may pass from the anterior condylar foramen 
to the jugular notch of the occipital. 

Describe the temporo -maxillary articulation. 

The ligaments are — capsular, inter articular fibre-cartilage, and acces- 
sory, which include external lateral, internal lateral, short internal lat- 
eral, and stylo-maxillary. 

The capsule is very thin and loose : it passes from the edge of the 
glenoid fossa to the interarticular cartilage, thence to the neck of the 
condyle. 

The interarticular disk or fibre-cartilage is placed horizontally between 
the jaw and temporal bone, concavo-convex above and concave below. It 
is connected in front with the external pterygoid muscle : it is composed 
of concentric fibres ; its circumference is thick, and its centre may be 
perforated. 

There are two synovial membranes : the upper is the larger and pro- 
longed in front, while the lower is smaller and prolonged behind. 

The external lateral ligament (lig. accessorium laterale) passes from 
the outer surface of the" z} r goma and tubercle, their lower border, down 
and back to the posterior surface of the neck of the lower jaw. Exter- 
nally it is in relation with the temporal fascia, and internally with the 
joint capsule. 

The internal lateral ligament (lig. acces. mediale) has two parts: one 
passes from the inner margin of the glenoid fossa to the neck of the 
condyle behind the insertion of the external pterygoid muscle ; this is in 
immediate relation to the capsule and known as the short internal lateral 
ligament. The other part passes from the spine of the sphenoid to the 
lingula and inner margin of the dental foramen (spheno-maxillary). Be- 
tween these two ligaments are the internal maxillary artery and veins, and 
lower down the auriculo-temporal and inferior dental nerves ; internal to 
the long band is the internal pterygoid muscle. Between the short in- 
ternal lateral and the synovial membrane is a pad of soft elastic connective 
tissue united to the periosteum of the posterior half of the glenoid 
fossa : this is compressed or stretched according to the position of the 
condyle. 

The stylo-maxillary ligament (stylo-myloid) has nothing to do with 
this articulation : it is a band of cervical fascia connected at one end by 
aid of the stylo-glossus muscle to the styloid process, and by the other 
to the angle and posterior border of the lower jaw. It separates the 
parotid from the submaxillary gland. 



104 ARTICULATIONS OF THE UPPER EXTREMITY. 

A hyoid ligament may be described here, the stylo-hyoid, which con- 
tinues the styloid process down to the lesser cornu of the hyoid bone : 
it is often ossified in man, and usually is in many animals, as the epihyal 
bone. 

The pterygo-maxillary ligament passes from the apex of the internal 
pterygoid plate to the posterior extremity of the internal oblique line of 
the iower jaw : it separates the buccinator from the superior constrictor 
of the pharynx. 

Origin. Insertion. 

Sphenomaxillary ligament, spine of sphenoid. Dental foramen. 
Pterygo- " " int. pterygoid plate. Alveolar border of lower jaw. 

Stylo- " " styloid process. Angle lower jaw. 

Stylo-hyoid " " Lesser cornu of hyoid bone. 

Nerves of the joint are the auriculotemporal and masseteric from the 
inferior maxillary. Arteries are temporal, the deep auricular, and tym- 
panic branches of the internal maxillary. _ Actions of the joint are protru- 
sion and retraction, elevation and depression, or a rotation when one side 
acts. The movements in the superior and inferior compartments are of 
different kinds : in the upper the fibro-cartilage glides forward and back- 
ward, and in the lower the condyle rotates against it on a transverse axis. 
Elevation and depression take place on a transverse axis through the cen-. 
tres of the rami — some say through the interarticular cartilages. If the 
depression be considerable, the condyle also has a gliding motion, carrying 
the cartilage with it. Rotary movement to one or other side takes place 
on an axis through the opposite condyle. Depression is produced by 
the weight of the jaw, platysma, digastric, mylo-hyoid, and genio-hyoid 
muscles ; elevation by the temporal, masseter, and internal pterygoid ; 
protrusion by external pterygoid, internal pterygoid, and superficial 
fibres of masseter ; retraction by deep fibres of masseter and posterior 
fibres of temporal. 

ARTICULATIONS OF THE UPPER EXTREMITY. 

THE SHOULDER GIRDLE. 
What are the proper ligaments of the scapula ? 

Coraco-acromial, superior and inferior transverse, and glenoid. 

The coraco-acromial ligament is a thin triangular band attached by its 
apex to the summit of the acromion in front of and beneath the clavic- 
ular articulation, and by its base to the whole length of the outer border 
of the coracoid process : it completes a vault for the protection of the 
head of the humerus. Above it is the deltoid, and below it the supra- 
spinatus muscle. The subacromial bursa separates it above from the 
acromion and acromial end of clavicle, and below the bursa covers the 
capsule over the head of the humerus and spreads out between the in- 
fraspinatus and supraspinatus muscles. 



THE SHOULDER GIRDLE. 



105 



The superior transverse ligament (suprascapular) is a flat shining band 

passing between the inner margin of the scapular notch and the root of 
the coraooid. As a rule it lias two parts (t. S., Fig. 8) — an upper, longer 

Fig. 8. 




Ligaments of Scapula. 

and stronger and tying in a plane with the surfaces of the supraspinous 
fossa and somewhat oblique; a lower part, thin, horizontal, and more 
anterior than the upper. Above the ligament are the suprascapular 
artery and one of its venae comites ; between the two parts are the supra- 
scapular nerve and the other suprascapular vein ; beneath the lower arm 
of the ligament are two veins passing to a venous plexus in the sub- 
scapular fossa. 

The inferior transverse ligament (t. I. ) (spino-glenoid) is in the great 
scapular notch, and passes from the base of the spine of the scapula to 
the posterior surface of the head of the scapula. This may be a feeble 
band of fatty tissue or a strong one of connective tissue : beneath it 
anastomotic vessels run from one spinous fossa to the other. The 
glenoid ligament will be described with the shoulder-joint. 

Describe the sterno-clavicular ligaments. 

The ligaments are capsular, interarticular fibro-cartilage ; accessory are 
interclavicular and costo-clavicular. 

Henle describes a capsule for this joint made up mostly of strengthen- 
ing bands : it is weakest at the lower anterior angle. In front a band 
called the anterior sterno-clavicular ligament passes from the inner ex- 



106 ARTICULATIONS OF THE UPPER EXTREMITY. 

tremity of the clavicle obliquely down and in to the upper part of the 
manubrium ; the post, sterno-clav. Kg. passes in a similar direction, and 
is related behind with the sterno-thyroid and sterno-hyoid muscles. 

The interarticular cartilage is attached above to the upper and poste- 
rior border of the inner extremity of the clavicle, and below to the junc- 
tion of the first costal cartilage with the sternum, and by its circumfer- 
ence to the capsule: thus the cartilage of the first rib is partly within 
this joint. Its circumference is thicker than its centre, which may be 
perforated : in size and shape it varies greatly. It lessens the inequal- 
ities of the two bony surfaces, and divides the joint into two parts, each 
provided with a synovial membrane. In young bones the interclavicular 
notch on the sternum is covered with hyaline cartilage. 

The interclavicular ligament is a flat band passing in a curved direc- 
tion between the inner extremities of the clavicles, and is closely attached 
to the upper border of the sternum. Some of its fibres are connected 
with the periosteum of the posterior surface of the sternal end of the 
clavicle, and some with the back of the capsule. So if we follow the 
course of the connective tissue from the upper border of the clavicle, 
some goes to the interarticular cartilage, some to the capsule, and some 
forms the interclavicular ligament. 

The costo-clavicular ligament is of rhomboid form, ascending obliquely 
from the inner part of the cartilage of the first rib back to the depression 
on the under surface of the sternal end of the clavicle. To its outer side 
is the subclavian vein. This ligament encloses the tendon of insertion 
of the subclavius muscle, but most of the ligament is behind the muscle, 
its anterior part being continued as fascia over it. Between the muscle 
and the posterior part of the ligament is sometimes developed the 
"bursa of Monro." Cruveilhier describes this ligament and bursa as 
the costo-clavicular articulation. 

Nerves, second and third cervical by descendens noni. Artenes, neigh- 
boring muscular branches. Motion is not a gliding, but axial on the 
fibro-cartilage. Elevation and depression of the shoulder produce move- 
ment here on a transverse axis through the costo-clavicular ligament ; 
movement of shoulder forward or backward, on a vertical axis through 
the same point. 

Describe the acromio-clavicular ligaments. 

Ligaments are capsular, interarticular fibro-cartilage ; accessor are 
posterior coraco-clavicular or trapezoid and conoid, and anterior coraco- 
clavicular. 

There is a weak capsule to this joint, really a fibrous covering of the 
synovial membrane : it is strongest above, being strengthened above and 
below by bands designated by some as the superior and inferior acromio- 
claviodar ligaments. The interarticular cartilage is usually present in 
some form, either hanging from the edge of the clavicle in the upper 
part of the joint or covering the whole articular surface of the acromion, 
or in 3 out of 400 cases wholly dividing the joint into two cavities. 



THE SHOULDER GIRDLE. 107 

The synovial membrane is usually single, or double when the inter- 
articular cartilage is complete. 

The coraeo-davicular ligaments connect the clavicle more firmly with 
the scapula: there are three. The posterior coraco-clavicular comprises 
the trapezoid ami conoid. The trapezoid is external, and attached below 
to the upper surface of the coracoid, and above to the oblique line pass- 
ing forward and outward on the under surface of the clavicle. Its outer 
border is free, and its internal border unites with the conoid, forming an 
angle projecting backward. This checks forward movement of the 
clavicle. 

The conoid is posterior and internal, and attached by its apex to the 
base of the coracoid, and by an expanded base to the conoid tubercle 
and a line internal to it on the under surface of the clavicle. This checks 
backward movement of the clavicle. Between these two ligaments a 
bursa may be developed, and between them is also the extremity of the 
subclavius muscle. 

The anterior coraco-clavicular ligament (Henle) is a shining thin band 
of connective tissue passing from the apex of the coracoid up and into 
the under surface of the clavicle. At its origin it is connected with the 
fascia over the pectoralis minor, and at its insertion with the fascia over 
the subclavius, from which it is separated in part by a layer of fatty 
tissue. 

An occasional scapuloclavicular ligament has been described passing 
from the upper border of the scapula internal to the notch to the acro- 
mial end of the clavicle. 

Nerves, suprascapular and circumflex. Arteries, suprascapular and 
acromial thoracic. Movements of joint, gliding and rotation. 

Describe the ligaments of the shoulder-joint. 

The ligaments are, capsidar, glenoid, coraco-humeral, coraco-glenoid, 
transverse humeral, glenoideo-humercd or Flood's, and the glenoideo- 
brachial internal and inferior of Schlemm. 

The strengthening bands are parts of the capsule, and not accessory 
ligaments so called. 

This is a ball-and-socket joint, peculiar (1 ) in the large size of the head 
of the humerus and shallowness of the glenoid cavity ; (2) loosenessof 
the capsule ; (3) intimate relation of muscles with capsule ; (4) relation 
of biceps tendon to joint. The glenoid articular cartilage is thinnest at 
its centre, ^ inch (1 mm. ) ; that on the head of the humerus is thickest 
at the centre, -^ inch (2 mm. ). 

The capsule encircles the articulation, attached above to the margin of 
the glenoid beyond the glenoid ligament, and below to the anatomical 
neck of the humerus. It allows the bones to be separated more than an 
inch : it is strengthened by tendons of muscles which may be reck- 
oned as ligaments — viz. above by the supraspinatus and tendon of biceps, 
externally by the infraspinatus and teres minor, below by the Jong head 
of the triceps, and internally by the subscapulars. There is a weak 



108 



ARTICULATIONS OF THE UPPER EXTREMITY. 



place in the capsule uncovered by muscle between the edges of the teres 
major and subscapulars ; vessels and nerves enter here (Al, Fig. 9). 

The superficial fibres of the capsule are longitudinal, and deeper ones 
are circular, funning a truncated cone with its narrow end toward the 
scapula. Below are folds in the capsule which become straight in raising 
the arm. 

The glenoid ligament is a fibro-cartilaginous rim attached to the mar- 
gin of the glenoid fossa to form a deeper cavity : it is triangular on sec- 
tion, and £g inch ( 3 mm. ) broad at its base. It is partly formed by the biceps 
tendon above as it bifurcates at its attachment, and by the triceps below, 
the fibres being arranged in concentric rings. Its intrinsic fibres are 
fused with the capsule. 

The synovial membrane lines the capsule and covers the outer side of 

Fig. 9. 




Left Shoulder-joint opened from Behind and Externally : 1, thickening of supraspinatus 
tendon; B, biceps tendon ; 2, glenoideo-humeral, or Flood's lig. ; 3, thickening of sub- 
scapular tendon; **, entrance to the subscapular bursa ; 4, inf. glenoideo-brachial of 
Schlemm, between 4 and 3, int. glenoideo-brachial of Schlemni ; * glenoid cavity; X cut 
surface of humerus; Isp, infraspinatus; Tin, teres minor; Tmj, teres major; Al, circum- 
flex vessels; Ab, short head of triceps. 



the glenoid ligament, and is continued a short distance over the cartilage 
on the head of the humerus. The long tendon of the biceps passing 
through the capsule is enclosed in a tubular sheath of synovial mem- 



THE SHOULDER G TEHEE. 109 

branc, and so does not really enter the synovial cavity. A rounded pro- 
trusion of synovial membrane, bursa intertubercularis, clothes the upper 
pari of the bicipital groove as tarns the insertion of the pect. major and 
latiss. dorsi. From within the tube of synovial membrane there passes 
to the tendon of the biceps a retinaculum of longitudinal bundles of 
connective tissue. 

Among the strengthening bands of the capsule is the coraco-humeral 
ligament, rising from the outer border of the coracoid, spreading out 
upon the upper and posterior wall of the capsule, and inserted into the 
great tuberosity of the humerus. The transverse humeral ligament is a 
part of the capsule between the tuberosities. The lig. coraco-glenoidale 
is a part of the coraco-humeral, rising with it and passing backward and 
outward at right angles from it on the surface of the capsule to the upper 
margin of the glenoid cavity. When the joint is viewed from the inside 
(Fig. 9), the glenoideo-Jiumeral, or Flood's ligament, is seen as a reflec- 
tion of the fibres of the coraco-humeral ligament through the capsular 
opening, passing up internal to the tendon of the biceps. 

The internal glenoideo-brachial ligament of Schlemm is a thin fold 
rising from a point above the entrance into the subscapular bursa, and, 
descending obliquely outward to be lost on the capsule beneath the sub- 
scapular tendon (is between (3) and (4) in Fig. 9), passes to the small 
tuberosity (Quain) ; The Ug. glenoideo-brachiale inf., or broad ligament 
of Schlemm (4), rises from the upper part of the glenoid ligament and 
passes down and out parallel to the internal lig. of Schlemm, and is lost 
on the circular fibres of the inner capsular wall. 

Quain calls the three ligaments last described the superior, middle, 
and inferior gleno-humeral ligaments. 

What holds the head of the humerus in place ? 

(1) Subscapular, supraspinatus, infraspinatus, deltoid, biceps, and tri- 
ceps muscles; (2) adhesiveness ; (3) atmospheric pressure. 

What are the communications of the joint ? 

Subscapular, infraspinatus bursse, biceps tendon, often the subcoracoid, 
coracoid, subacromial, and subdeltoid bursae. 

The nerves supplying the joint are circumflex and suprascapular. 

The arteries are anterior and posterior circumflex and suprascapular. 

The movements of the joint are in every direction. 

Flexion is possible to 45° without involving other joints, produced by 
the pectoralis major, anterior fibres of the deltoid, coraco-brachialis, and 
by the biceps if the elbow is fixed. This occurs on a transverse axis 
through the great tuberosity and glenoid cavity. Flexion is limited by 
tension of the posterior part of the capsule and by the small tuberosity 
abutting against the coracoid ; the movement is continued by rotation of 
the scapula. 

Extension through 15° is produced by the latissimus dorsi, teres major, 
posterior fibres of deltoid, and the triceps if the elbow is fixed. Exten- 



110 ARTICULATIONS OF THE UPPER EXTREMITY. 

sion is hindered by superior muscles and approximation of the" great 
tuberosity and acromion. 

Alxluction through 90° is performed by the deltoid, aided by the 
supraspinatus, on an antero-posterior axis through the anatomical neck 
of the humerus : further motion calls into play accessory joints — viz. 
the upper portion of the trapezius elevates the peak of the shoulder, 
and the lower fibres of the serratus magnus pull the inferior angle of 
the scapula forward, rotating that bone, which raises its external angle. 
Two other joints share the motion — the acromio-clavicular till its yield- 
ing is stopped by the coraco-clavicular ligaments, next the sterno-clavic- 
ular joint till its motion is checked by the costo-clavicular ligament. So 
three chief muscles are concerned in raising the hand above the head, 
and two joints besides the shoulder-joint. Freest motion is up and for- 
ward. The angle between the scapula and clavicle changes to secure 
adaptation of the former to the chest- wall. 

Adduction is accomplished by the subscapularis, pectoralis major, 
latissimus dorsi, and teres major. Total rotation is through 90°, limited 
by capsule and muscles : it is freest externally and backward ; rotation 
in is produced by the subscapularis, latissimus dorsi, and teres major ; 
rotation out by the infraspinatus and teres minor. Circumduction is a 
combination of all the angular movements in succession. 

THE ELBOW AND FOREARM. 
Describe the elbow-joint. 

The elbow is a hinge joint with screw-like surfaces : really three joints 
are involved, the ginglymus screw, the radio-humeral, and the radio- 
ulnar. The lesser sigmoid of the ulna and the articular surface of the 
radius are parts of cylindrical surfaces, the latter an arc of 1 80°, the 
former of 90° and radius of % inch (12 mm. ). The diameter of the curve 
on the humerus at the inner edge of the trochlea is 1 6 mm. , of the groove 
of the trochlea 11 mm., of the outer edge of the trochlea 13 mm., and of 
the capitellum 12 mm. The articular cartilage in the elbow-joint is 
hyaline and 2 mm. thick. Only so much of the trochlea is covered by 
cartilage as is embraced by the sigmoid cavity when the forearm is flexed 
to 90° : the parts remaining free, anteriorly and posteriorly, are covered 
with periosteum and fatty pads. 

The ligaments are capsidar, with thickened bands and the orbicular 
ligament; the thickened bands are known as anterior and posterior, in- 
ternal lateral and external lateral. The radial insertion of the capsule 
is the orbicular ligament surrounding the head of the radius ; the cap- 
sule includes the coronoid and part of the olecranon fossne, a part of the 
internal epicondyle, but not the external, the tips of the coronoid and 
olecranon processes. 

The anterior thickened portion of the capsule passes from the point of 
the inner epicondyle and from the front of the humerus above the coronoid 
fossa to the anterior margins of the coronoid process, and externally into 



THE ELBOW AND FOREARM. Ill 

the orbicular ligament. Superficially is an oblique band passing down and 
out from the internal epicondyle to the orbicular ligament. The fibres 
under these are vertical, the anterior ligament of Barkow, and the deepest 
are transverse. The 'posterior part of the capsule passes to the margin 
oi' the olecranon process from the lower end of the humerus, leaving the 
upper part of the fossa exposed. The lowest fibres are transverse, bridging 
over part of the olecranon fossa ; the upper fibres are vertical, thickest 
in the median line, and pass through a tatty pad in the upper part of 
the fossa. These vertical fibres are BarJcow's posterior straight cubital 
ligament : on either side of it the capsule is as thin as a bursa. 

The internal lateral ligament is fan-shaped, rises from the lower and 
back part of the root of the inner epicondyle, and consists of three por- 
tions: (1) a posterior humero-olecranon part, helping form the groove 
for the ulnar nerve; (2) an anterior humcro- cor onoid part ; and (3) an 
olecrano-coronoid portion, deepening the sigmoid cavity. 

The external lateral ligament is not so distinct as the internal, is at- 
tached above to a depression below the external epicondyle, and below to 
the orbicular ligament and posterior interosseous border of the ulna (not 
into the radius, or its rotation would be impaired). It gives some strength- 
ening bands to the anterior ligament, forming a cruciform arrangement. 
The supinator brevis rises from this ligament in part. The brachialis 
anticus muscle inserts a band into the anterior ligament, the triceps a 
band into the posterior. The anconeus rises from the capsule between 
the external condyle and external border of the olecranon. 

The orbicular ligament, lig. annulare radii, is the thickest part of, and 
is the inferior radial edge of, the capsular. It is f inch ( 1 mm. ) broad, 
and is the only ligament of the superior radio-ulnar articulation which is a 
lateral ginglymus joint. _ The ligament is attached by each end to the ex- 
tremities of the small sigmoid cavity, surrounds the head of the radius, 
forming four-fifths of a circle. It is broader in the upper part of the cir- 
cumference than below, grasping the head of the radius more firmly. 
The supinator brevis, extens. carpi uln., extens. min. dig., and extens. 
com. dig. rise in part from the orbicular ligament. 

The synovial membrane is extensive, lines the capsule and orbicular 
ligament, entering into the articulation between all three bones. 

There are inequalities between the sigmoid fossa and trochlea which 
are filled in with synovial membrane or fatty pads : there is another pad 
in the small sigmoid cavity. The capsule is reinforced by intra- and ex- 
tracapsular pads, both in the coronoid and olecranon fossae. This allows 
free gliding of muscles. The triceps pulls up the wrinkled capsule in 
extension, the brachialis anticus in flexion. 

The muscles in relation to the joint are, in front, the brachialis anti- 
cus ; behind, the triceps and anconeus ; externally, the supinator brevis 
and supinato-extensor group ; internally, the pronato-flexor group. 

What bursse are related to the joint ? 

(1) Superficial olecranon between tendon of triceps and skin ; (2) deep 



112 ARTICULATIONS OF THE UPPER EXTREMITY. 

olecranon, between tendon of triceps and bone; (3) at inner margin of 
brachials anticus; (4) bicipital bursa, between tendon of biceps and 
bone; (5) epicondylar bursas, subcutaneous; (0) sometimes a retro-epi- 
trochtear behind the inner epicondyle, related to the ulnar nerve. 

Nerves are from the ulnar, median, musculo-spiral, internal cutaneous, 
and nerve of CruVeilhier (from the branch of the musculocutaneous to 
the biceps). 

Arteries are derived from an anastomosis between the inferior and su- 
perior profunda, anastomotica magna, anterior and posterior ulnar recur- 
rent, interosseous recurrent, and radial recurrent. 

Action. — The humero-ulnar joint possesses flexion and extension, no 
lateral movement or rotation. 

Flexion of 150° is possible, produced by the supinator longus, biceps, 
brachial] s anticus, and muscles from the inner condyle : it is checked by 
contact of soft parts, posterior part of capsule, and posterior part of in- 
ternal and external lateral ligaments, not by bone. 

Extension (after flexion) goes through 150° by the triceps, anconeus, 
extensors of the wrist, and common extensors of fingers : it is checked 
by the anterior part of the capsule and anterior parts of the external 
and internal lateral ligaments, not by bone. 

Supination (rotation out) and pronation (rotation in) occur through 
90° in the radio-ulnar and radio-humeral joints on an axis through the 
head and neck of the radius and styloid process of the ulna. Supina- 
tion is performed by the biceps strongly, by the supinator longus and 
brevis and extensors of the thumb ; pronation by the pronator radii teres 
and pronator quadratus: in this last motion there is a "winding up" 
of the biceps and supinator brevis. These rotary movements are 
checked by the oblique ligament, orbicular, and capsular, by the inter- 
osseous membrane, by the inferior articulation, and by muscles. If 
sliding of soft parts on the ulna is hindered, pronation and supination 
are largely checked. 

Experiment. — Thrust the hand pronated through a round hole in a 
board : if it be the right hand, mark on the board the position of the 
styloid process of the ulna, as at a. Supi- 
nate the hand, and the ulnar styloid pro- 
cess will be found at b. 

What is the explanation if the ulna has 
no lateral motion ? 
The first movement back from a is of ex- 
tension, which occurs at the elbow-joint ; 
the next, near c, is adduction, and occurs 
at the shoulder- joint; the final movement 
to b is flexion at the elbow ; When ro- 
tated back again we have extension, abduction, and flexion in order. 
If now the humerus be firmly fixed as in a vice, so as to prevent 
ad- and abduction at the shoulder-joint, the styloid of the ulna will 




THE WRIST AND CARPUS. 113 

not change position, and the experiment could not be done in the above 
aperture. 

Describe the accessory ligaments of the bones of the forearm. 

(1) Oblique; (2) interosseous. The oblique //(/anient (chorda trans- 
versalis) is a flatly-rounded cord running from the tubercle of the ulna 
on the eoronoid process down and out to a point on the radius a little 
below the bicipital tuberosity. Its fibres have an opposite direction to 
those of the interosseous ligament. The oblique may be wanting, or may 
exist as a tendinous slip to the flexor long. poll. ; it may be double, the 
upper band passing from the small sigmoid notch and orbicular ligament 
to a point above the bicipital tuberosity. 

The interosseous ligament (membrane) connects the interosseous ridges 
of the radius and ulna. The fibres pass down and in to the ulna in such 
a direction that if the hand press against resistance the radius would 
drag the ulna after it. The ligament is divisible here and there into sev- 
eral layers, some fibres coming from the anterior surface of the radius. 
It is deficient above, commencing on the radius at the insertion of the 
oblique ligament, leaving a space between the two for the posterior in- 
terosseous vessels. Just above its lower end is an oblique opening be- 
tween two layers of the ligament for the passage of the anterior interos- 
seous vessels. The lower edge is almost vertical, the fibres ending higher 
on the ulna than on the radius and running in a direction opposite to the 
fibres above : this lowest split between the ligament and ulna is filled 
with fat and covered by the pronator quadratus muscle. Some fibres go 
to the posterior annular ligament. The object of the ligament is mus- 
cular attachment with economy of weight. 

Describe the inferior radio-ulnar articulation. 

A lateral ginglymus joint between the head of the ulna and sigmoid 
cavity of the radius. The ligaments are the anterior and posterior radio- 
ulnar and triangular fibro-cartilage. The anterior and posterior liga- 
ments are narrow bands passing transversely over the joint, as indicated 
by their names. The triangular ligament is placed beneath the ulna, 
attached by its apex to the base of the styloid process ; its under surface 
articulates with the cuneiform. The synovial membrane is very exten- 
sive, the membrana sacciformis. 

Actions are supination and pronation. 

THE WRIST AND CARPUS. 
Describe the radio-carpal or wrist-joint. 

_ This is a condyloid articulation between the radius and triangular car- 
tilage above, the scaphoid, semilunar, and cuneiform below. 

The ligaments are external and internal latered, anterior, and poste- 
rior. The two former are rounded cords passing respectively from the 
styloid process of the radius and ulna to the end carpal bones of the first 
8— A. 



114 ARTICULATIONS OF THE UPPER EXTREMITY. 

row. The anterior ligament is a broad membranous band connecting 
the anterior surfaces of the bones forming the articulation. The poste- 
rior ligament is less strong than the anterior, and passes from the radius 
to the dorsum of the first three carpals. • 

Mention the ligaments of the carpus. 

There arc three sets: 1, articulations of first row have two dorsal, two 
palmar, and two interosseous ligaments ; 2, articulations of the second 
row have three dorsal, three palmar, and three interosseous ligaments; 
3, articulations of the two rows with each other have anterior, posterior, 
external lateral, and internal lateral ligaments. 

What are the ligaments connecting the carpus with the meta- 
carpus ? 

The first metacarpal bone and the trapezium have a capsule and 
separate synovial membranes. The joints between the carpus and four 
inner metacarpals have dorsal, plantar, and interosseous ligaments. 

The synovial membranes of all the joints in the carpus and wrist proper 
are Jive in number. 

What are the remaining ligaments of the metacarpus and 
phalanges ? 

Of the metacarpals with each other, there are the dorsal, palmar, and 
interosseous ligaments : their digital extremities are connected by a nar- 
row band, the transverse ligament, presenting four grooves for tendons. 

The metacarpophalangeal articulations have anterior and two lateral 
ligaments. The interphalangeal articulations also have anterior and two 
lateral ligaments. 

Henle's Description of the Wrist- or Hand-joint. 

This includes the lower radio-ulnar articulation, the articulation of the 
forearm with the carpus, the intercarpal and carpo-metacarpal articulations. 
Their movements are all mutually compensatory, and many ligaments are 
common. To the humerus is attached the ulna, to the ulna the radius, and 
to the radiusthe hand. 

1. The lower radio-ulnar is a rotation joint. The curve of the ulnar articu- 
lar surface and that of the sigmoid cavity are not concentric arcs, the former 
being a half-circle of f inch (16 mm.) radius, and the latter an arc of 45° of 
1 inch (26 mm.) radius. The ligaments are capsular and interarticular : the 
latter is not interarticular in the usual sense, but is an extension inward of 
the lower end of the radius. At its base it is attached to a prominent edge of 
the radius below the sigmoid cavity ; at its apex it is attached by two bands, 
an upper to a little cavity at the base of the styloid, and a lower to the outer 
surface of that process : vessels pass between the two bands. Its upper sur- 
face articulates with the head of the ulna ; its lower is concave and forms 
part of the carpal joint. It is perforated in the centre in 40 per cent, of cases, 
and is £ inch (5 mm.) thick at its apex. 

The capsule is strong, and continuous below with that of the radio-carpal 
joint : anteriorly some fibres of the pronator quadratus are attached, by which 



THE WRIST A XT) CARPUS. 115 

it is pulled forward in pronation ; posteriorly it is strengthened by oblique 
and transverse fibres, and is covered on the ulnar side by the common carpal 
ligament (annular). It passes between the bones of the forearm about l inch 
(5 mm.) above the cartilaginous surfaces, ending in a blind sac. The synovial 
processes vary in number and form : thin threads or tabs or strong folds rise 
from the posterior and inner capsular wall. 

2. Radio-carpal Joint. — A line passing between the radius and ulna divides 
the lunar bone, so that the scaphoid and outer half of the lunar articulate 
with the radius; the inner half of the lunar and the pyramidal articulate 
with the triangular fibro-cartilage. The carpal bones of this joint are con- 
nected by strong interosseous ligaments flush with the upper articular sur- 
faces. The extent of articular surface on the carpus is greater than that on 
the forearm, but the convexity is smaller than the concavity, so that contact 
is mesial, with room for lateral synovial pouches. The frontal arc of the 
joint-surface of the radius is 69° of If inches (42 mm.) diameter ; the sagittal 
arc is 64° of $ inch (18 to 22 mm.) diameter." 

The capsule is pretty firmly stretched from the edges of the upper to the 
edges of the lower joint-surfaces: it is shortest and least yielding between 
the radius and lunar, serving as an axis of rotation. The strengthening 
fibres of the capsule are continuous with those of the joint above. Synovial 
folds are in the posterior and ulnar corners of the joint-cavity : synovial 
bands with concave edges (ligg. mucosa), in connection with the interosseous 
ligaments of the first row, spring from the anterior and posterior parts of the 
capsule. This joint may communicate with that of the pisiform or with the 
carpal joint by the lack of an interosseous ligament. 

3. Carpal Joint. — This is between the bones of the lower row and those of 
the upper, excepting the pisiform. The trapezoid and trapezium are con- 
nected at their lower edges by a thin interosseous ligament: there is none 
between the trapezoid and os magnum, where the carpal as a rule commu- 
nicates with the carpo-metacarpal joint ; the cleft between the os magnum 
and unciform is closed by a large mass of connective tissue prolonged as a thin 
membrane between their articular surfaces. The articular cartilages of all the 
carpal bones are hyaline, and fe inch (i to 1 mm.) thick. The head of the os mag- 
num projects into the cavity of the scaphoid and lunar, allowing flexion, ex- 
tension, and rotation and lateral immobility: the axis of rotation is through 
the length of the os magnum, that of flexion and extension across its head. 

The capsule of this joint includes the edges of the cartilaginous surfaces. 
It shows transverse folds anteriorly in flexion and posteriorly in extension. 
Synovial folds fill the corners and clefts between the bones. 

4. The pisiform joint has a weak capsule, attached at some distance from the 
articular surfaces of either bone (4 mm. distant from that of the pisiform). 

5. The General Carpo-metacarpal Joint. — This is made up of very irregular 
joint-surfaces covered by hyaline cartilage I to I mm. thick. 

The capsxde is strong, and fastened immediately to the edge of the carti- 
laginous surfaces by which the bases of the metacarpals articulate with each 
other and with the carpus. The pouch between the bases of the third and 
fourth metacarpals is divided by an interosseous ligament into two parts, an 
anterior and posterior. In this same region a sagittal synovial fold passes up 
between the os magnum and unciform, and may completely divide the carpo- 
metacarpal joint. 

6. The thumb-carpal joint is elliptical, saddle-shaped, so that the convexity 
of each surface seems to be received into the cavity of the other : it makes 
an angle of 45° with the horizontal, the external edge being the highest. 

The capsule is attached close to the joint surface of the trapezium, but about 



116 ARTICULATIONS OF THE UPPER EXTREMITY. 

£ inch (5 mm.) away from that of the first metacarpal. A synovial fold 2 mm. 
broad extends around the joint-cavity, weakest on the radial side. 

The nerves of the above joints are from the ulnar, median, and posterior 
interosseous. 

Arteries of the radio-carpal joint are from the anterior and posterior carpal 
arches, the radial and ulnar ; for carpal and carpo-metacarpal are anterior and 
posterior carpal arches, anterior and posterior interosseous, and deep palmar 
arch. 

Actions. — In the radio-carpal joint there is flexion associated with adduction, 
extension associated with abduction : adduction is possible to 45°, as the ulna 
does not descend so low as the radius; abduction is slight ; flexion is less than 
extension. When the hand is flexed, it cannot be ad- or abducted, as the 
lateral parts of the capsule are taut. There is no rotation provided, as the 
pronation and supination of the radius answer that purpose. 

In the carpal joint flexion is freer than extension ; rotation is present, but 
no lateral motion. 

In the carpo-metacarpal joint there is some flexion and extension on a trans- 
verse axis, possibly a little rotation on a long axis. Movements are freest at 
the margins of the metacarpus and least in the centre ; the excursion of the 
metacarpal of the middle finger does not exceed 6°. 

The synovial cavities are five in number: (1) between radius and ulna, ulna 
and fibro-cartilage ; (2) in radio-carpal joint; (3) in carpal joint and carpo- 
metacarpal; (4) in thumb-carpal joint; (5) in pisiform joint. 

ACCESSORY LIGAMENTS OF THE WRIST. 

(a) What is generally known as the annular ligament is partly fascial and 
partly ligamentous. The fascial portion is only transverse bauds of the fascia 
of the forearm, and is called the lig. carpi commune. There is no natural, 
but a practical, division into anterior and posterior parts (radial and ulnar). 
The highest bundles of the idnar portion begin in the middle of the posterior 
surface of the forearm 1 inch above the radio-carpal joint, and run obliquely 
inward and down to the ulnar margin of the wrist, and are inserted into the 
extensor carpi ulnaris tendon. The next lower set of fibres rise from the 
prominent ridge on the radius, bounding externally the groove for the ex- 
tensor sec. inter, poll., and pass around internally to the summit of the pisi- 
form. Farther down follow fibres from the styloid process of the radius to 
the pisiform and ulnar edge of the fifth metacarpal. The fibres passing to the 
pisiform stop there ; those above and below this are continued externally, so 
that a cleft is left through which the ulnar nerve and vessels pass from be- 
neath the deep fascia. 

The radial portion of the common carpal ligament passes from the ridge on 
the radius adjacent to the extensor secundi poll, tendon, over the other two 
extensors of the thumb, becomes continuous with the fascia over the ball of the 
thumb, passes over the radial vessels and tendon of the flexor carpi rad., and here 
unites in part with the tendinous layer of the "proper volar lig. of the carpus ;" 
it passes on ulnarward, and divides into a superficial and deep layer, the former 
going to the summit of the pisiform, covering the ulnar nerve aud vessels, the 
latter passing beneath them to join the ligamentous portion of the annular 
ligament — i. e. the lig. c volare proprium. In front of the flexor tendons 
are therefore two ligaments, grown together, only separable by the knife in 
the region of the palmaris longus ; the superficial one is fascia, lig. c. commune, 
the deep one is ligamentous, the lig. c. vol. proprium, and both together form 
the anterior annular ligament of Gray. 

(b) Accessory Bands of the Dorsal Surface. — On the back of the wrist, between 



ACCESSORY LIGAMENTS OP THE WRIST. 



117 



the lig. c. COmm. (posterior annular lig..) and the joints, is a layer of Patty con- 
nective tissue containing vascular network, cushioning the grooves and form- 
ing partition walls between some of the extensor tendons: some of it passes 

Fig. 10. 




Dorsal Surface of Wrist. 



down into strengthening bands of the capsules. 1. Deep dorsal ligament of the 
carpus (lig. carpi dorsale profundum), Fig. 10. This consists of (1) nearly- 
straight fibres from the ulna to the pyramidal (py) ; (2) three bundles of con- 
verging and arched fibres to the pyramidal from the lower margin of the ra- 
dius, its styloid process, and the scaphoid ; (3) straight fibres from the styloid 
of the radius to the scaphoid (s) ; thence to the trapezium and trapezoid ; (4) 
from the lowest arched band slips go to the os magnum and unciform ; (5) a 
broad band (*) from the pyramidal to the unciform, thence to the base of the 
fifth metacarpal ; (6) sometimes a narrow band (**) from the radius to the os 
magnum. 

2. Short Dorsal Ligaments of the Carpus (ligg. carpi dorsalia brevia). — These 
include all which connect adjacent bones — viz. ligg. intercarpea, carpo-meta- 
carpea, and intermetacarpea. The dorsal intercarpals are flat, transverse, or 
oblique, and only in the lower row ; those seen in the upper row are posterior 
edges of interosseous ligaments. The dorsal carpo-metacarpalspass obliquely 
between the parts indicated (Fig. 10) ; as a rule each metacarpal is united to 
two carpals, only one for the first. These ligaments on the second, third, and 
fifth metacarpals are united with the radial and ulnar extensors. The dorsal 
intermetacarpals are transverse bands (Fig. 10) between the metacarpal bases, 
four in number; the one between the thumb and index is of varying strength. 

(c) Accessory Bands of the Anterior Surface. — 1. The proper volar ligament of 
the carpus (lig. carpi volare proprium). This forms a bridge over the ante- 
rior hollow of the carpus, and a great support to the upper part of the hand ; 
it may be called the ligamentous portion of the annular ligament. On the 
ulnar side it rises from the radial edge of the pisiform, from the hook of 
the unciform, and from the piso-unciform ligament, and sometimes from the 



118 ARTICULATIONS OF THE UPPER EXTREMITY. 

bases of the fourth and fifth metacarpals; radially it rises from the styloid 
process of the radius, the radio-carpal joint capsule, the tuberosity of the 
scaphoid and trapezium, and base of the first metacarpal. Besides these at- 
tachments, it is connected with the deep volar lig. on either side, the two 
together forming the canal for the passage of the flexor tendons. The middle 
third of the ligament is connected with the lig. c. coram, and palmaris long. 
tendon ; below it is continuous with the deep layer of the palmar fascia. 

2. The deep volar ligament of the carpus (lig. carpi volare profundum, Vpr, 
Fig. 11). There is a fascia continuous with that covering the pronator quad- 
ratus passing over the hand-joints to the anterior surface of the palmar inter- 
ossei : if this be removed, there is left a shining, strong, ligamentous mass 
divisible into three parts — the arcuate above, the radiate in the middle, and 
the transverse below (lig. carpi v. profundum arcuatum, radiatum, and trans- 
versuni). 

(1) The upper fibres of the arcuate (Vpa) pass transversely on the capsule 
from the lower end of the radius to the triangular fibro-cartilage ; (2) the 
next set pass in an arched manner from the styloid of the radius to the pyra- 

Fig. 11. 




Palmar Surface of Wrist. 

midal ; they there unite with (3) straight fibres from the base of the styloid 
process of the ulua to the os magnum ; (4) fibres also pass from the styloid of 
the radius and from the cuneiform to converge upon the os magnum. 

The middle portion of this deep ligament (Vpr) sends its fibres radially from 
the os magnum in three directions, internally, externally, and downward. 
Those going straight down descend to the third metacarpal ; others, approach- 
ing a transverse direction, go to the second metacarpal on one side and the 
fourth and fifth on the other. The internal fibres go to the uuciform and its 
process, and upward to the pisiform joint, and there turn forward to form 
the proper volar ligament (ligamentous part of the annular). The external 



ACCESSORY LIGAMENTS OF THE WRIST. 119 

fibres go to the ulnar side of the flexor carpi radialis tendon, to the trapezoid 
and tuberosity of the scaphoid. 
The transverse portion (Vptj connects the hones of the lower row together, 

the bases of the metacarpals together, and these two sets of hones witli each 
other. The bundles form a triangular mass with its apex down and attached 
to the third metacarpal; the base is formed of transverse bands covered by 
the radiate ligament which pass from bone to bone between the trapezium 
and unciform, between the second and fifth metacarpals. The fibres from the 
third metacarpal go externally in two layers, a superficial one in /rout of the 
tendon of the flexor c. radialis (ei, Fig. 11), and into the lig. c. vol. proprium ; 
a (U ep one behind this tendon to the second metacarpal and trapezium ; of the 
internal fibres, the deepest go to the fourth and fifth metacarpals, and the su- 
perficial to the unciform and piso-metacarpal ligament. 

The height of the lig. c. vol. proprium is about 1 inch (28 mm.) — i. e. this is 
the length of the canal enclosing the flexor tendons and median nerve. The 
lower opening of the canal is f inch (21 mm.) in a transverse direction, § 
inch (11 mm.) in a sagittal direction. Diverging from the sides of this opening 
are the muscles of the little finger and those of the ball of the thumb. 

A carpo-metacarpal band, Cm, passes from the tuberosity and ridge of the 
trapezium to the base of the first metacarpal. 

(d) Accessory Ligaments of the Ulnar Side. — (1) Piso-hamatum (Ph, Fig. 11), 
from the apex of the pisiform to the hook of the unciform, united at its upper 
edge with the lig. c. vol. proprium; (2) lig. piso-metacarpeum (Pm), really a 
continuation of the flexor carpi uln. tendon, passes fan-shaped from the 
pisiform to the anterior surface of the base of the fifth, fourth, and third 
metacarpals; (3) lig. hamo-metacarpenm, Hm, passes from the ulnar surface 
of the hook of the unciform to the fifth metacarpal. 

(e) Accessory Ligaments of the Interspaces of the Metacarpals. — Ligg. inter- 
metacarpea interossea, connecting the bases of the metacarpals, strengthening 
the capsules below, and running from the posterior edge of the external bone 
to the anterior edge of the internal one. 

Metacarpophalangeal Articulations. — The head of a metacarpal bone with its 
hyaline cartilage forms a half-sphere of f inch (9 mm.) radius, with a segment 
cut off from each side. The concavity of the articulating phalanx is quite flat, 
and belongs to a curve of greater radius than the head it receives, (a) The 
capside is very thin, but strengthened on all sides by ligaments or tendons, and 
is lined by synovial tissue. In the thumb, sometimes index and little finger, 
are to be found in the anterior wall of the capsule sesamoid bones : their sur- 
faces, which lie in the joint-cavity, are covered with hyaline cartilage, and a 
synovial fold runs between them. 

(b) Accessory Bands. — Two lateral ligaments, lig. accessorium (radiale and 
ulnare) : these are rounded cords running on either side from the tubercle on 
the side of the head of the metacarpal and a little fossa in front of this to the 
base of the first phalanx. 

The anterior ligaments (ligg. capitulorum volaria) are made of transverse 
bands coming from several directions : the connective tissue covering the in- 
terossei presents near the heads of the metacarpals strong transverse fibres 
which pass over the capsule and between the capsules of the four inner meta- 
carpo-phalangeal joints. A part passes forward on either side, and forms a 
smooth tube for the flexor tendons over the joints, and for the lumbrical 
muscles over the ligg. capitulorum ant. The anterior walls of the tubes for 
the flexor tendons are the ligg. vaginalia, transverse bands fastened to the 
edges of the phalanx. These are also (ligg. dorsalia) connected with the ante- 
rior and side walls of the capsule, which pass back over the lateral ligaments 



120 ARTICULATIONS OF THE LOWER EXTREMITY. 

through some tendinous fibres of the interossei to the extensor tendons, which 
are enclosed by them, and thus held down for the protection of the back of 
the joint. Lower transverse dorsal bands (ligg. capitulorum dorsalia) are 
stretched from finger to finger between the ligg. dorsalia. 

Sometimes there are bursas between the adjacent joint-capsules at the lower 
ends of the metacarpals. 

The movements of these joints are flexion, extension, ad- and abduction, cir- 
cumduction, and rotation. When the finger is flexed, the lateral ligaments 
are tense and prevent ad- and abduction of fingers and rotation of the first 
phalanx on a long axis. 

Articulations of the Phalanges. — Capsular and accessory — two lateral, ligg. vagi- 
nalia, ligg. dorsalia, and retinacula tendinum (folds of synovial membrane). Ana- 
logues of the ligg. capitulorum (transverse ligament, Gray) remain as fibrous 
septa passing laterally from the capsules to the skin of the fingers. 

Movements are flexion and extension. 

ARTICULATIONS OP THE LOWER EXTREMITY. 

THE PELVIC GIRDLE. 
Describe the special ligament of the hip-bone. 

This is the obturator ligament, or membrane partly closing in the ob- 
turator foramen, presenting small holes here and there, in some places 
layers and a general horizontal direction. As it passes from one obtura- 
tor tubercle to the other it forms the obturator canal, passing down and 
forward, filled with fat, the obturator vessels, and nerve. Above and 
anteriorly the ligament is attached to the margin of the foramen on a 
plane with the anterior (really inferior) surface of the os pubis ; below 
and behind it is attached so as to be flush with the pelvic surface of the 
os pubis. From its inner margin rise fibres of the obturator internus 
muscle, and from the lower part of the outer margin fibres of the obt. 
externus. The upper part of the outer surface is filled by fat, which is 
covered by single flat bands going from the ligament to the external edge 
of the foramen and to the capsule of the hip-joint. 

The lig. iliacum proprium is sometimes stretched across the concavity of the 
ilio-pectineal line. 

Describe the ligaments between the two hip-bones. 

The only articulation is the symphysis pubis, which shows many vari- 
eties. The bone-surfaces are covered by layers of hyaline cartilage con- 
nected to the bone by nipple-like processes : these plates often contain 
bony kernels. The space between the cartilages is filled in part with 
fibro-cartilage and in part with clear fibrous substance ; the size of the 
space is greater in front and below where the edges diverge : in the pos- 
terior half of the synchondrosis the cartilages are parallel, and lie so close 
that the interposed substance looks like a fine white line. In the upper 
and back part of the interposed substance is a median split with smooth 
walls lined by elastic fibro-cartilage : up to the seventh year this cleft is 
occupied by fibrous substance containing little holes, which later unite 
into a larger cleft and may contain synovia. Whether this is more com- 



LIGAMENTS BETWEEN BONES OF TRUNK AND HIP-BONE. 1 21 

men in pregnancy is not settled: the cleft is not so often lacking in wo- 
men as in men. 

For ligaments Gray describes anterior, posterior, superior, and subpu- 
bic, and an interposed Jibro-carfMage. 

Henle finds that the cartilages are mainly continuous with the perios- 
teum and muscle-tendons of the region. _ The upper edge and posterior 
surface of the joint are covered only by periosteum, ^ inch (o mm. ) thick, 
consisting of transverse fibres. In front is a thick layer of connective 
tissue continuous with the periosteum, and the attachment of abdominal 
muscles and adductors of the thigh. In common with this is the Jig. arcu- 
atum pubis (posterior layer of triangular ligament), which is stretched 
between the rami of the pubis as a diaphragm to a point § inch (9 mm.) 
below the bony subpubic arch : only the middle part of the lower edge 
is free, limiting the hole through which passes the dorsal vein of the 
penis ; laterally it is continuous with the obturator internus fasciae. 



LIGAMENTS 



BETWEEN 
AND 



THE BONES 
HIP-BONE. 



OF THE TRUNK 



Fig. 12. 






Describe the ligaments of the ilio-sacral joint. 

Capsule, accessoiy are — ilio-lumbar, anterior, interosseous, and posterior 
ilio-sacral, great sacro-sciatic, small sacro-sciatic. 

The ilio-sacral joint (sacro-iliac) is between the auricular surface on the 
ilium and a corresponding one on the first three vertebrae of the sacrum : 
the cartilage is hyaline, 2 to 3 mm. thick on the sacrum and 1 mm. thick 
on the ilium. The sacrum is held in position mostly by ligament and 
partly by a sort of mortise between the bones (Fig. 12). 

The capsule is firmly stretched over 
the joint-cavity, strengthened exter- 
nally by horizontal fibres, within by soft- 
vascular connective tissue covered by 
periosteum. _ On the pelvic surface 
the capsule is not attached immedi- 
ately to the edges of the bones, but 
farther away, leaving a little space 
for S3'novia: small synovial tufts are 
found in this space and between 
the upper edges of the cartilaginous 
surfaces. 

Accessory Bands. — (1) llio-lumbar 
Ligament. — The posterior layer of the 
sheath of the quadratus lumborum 
muscle is the lumbo-costal ligament, 
being a union of representatives of the 
costo-trans verse and intercostal liga- 
ments of this region. The anterior 
layer of this sheath is thin above, and may be a part of the lumbo-costal 




Section through the Second Sacral Ver- 
tebra parallel to the Pelvic Inlet. 



122 ARTICULATIONS OF THE TOWER EXTREMITY. 

ligament, but belowit is called the iliolumbar. It rises in part from the 
anterior surface of the fourth lumbar, sonic fibres descending to the fifth 
transverse process : a strong falciform band envelops at its origin the trans- 
verse process of the fifth and passes out upon the crest of the ilium ; a part 
from the base of the fifth process descends into the pelvis, covers the upper 
part of the ilio-sacral joint, and is lost on the periosteum. These descend- 
ing bands (lumbo- sacral of Gray) represent anterior costo-transverse liga- 
ments, and form external boundaries to the openings through which pass 
the anterior branches of the fourth and fifth lumbar nerves. Inter- 
nal to these run flat bands vertically from the root of a transverse pro- 
cess and intervertebral cartilage to corresponding points next below: 
they serve as bridges over vessels and as heads of origin for the psoas 
muscle. 

(2) llio-sacral Ligaments. — The capsule of this joint is strengthened 
anteriorly by thin bands, the anterior ilio-sacral ligament. Posteriorly 
connecting the tuberosities of the two bones is a great number of flat and 
cylindrical bands separated by masses of fat : the whole mass is the in- 
terosseous ilio-sacral ligament. Two bands rise from the first and second 
articular processes of the sacrum, and a third very oblique one from the 
third process, and pass up to the posterior superior spine of the ilium : 
these are the posterior ilio-sacral ligaments. (3) The great sacro-sciatic 
ligament (posterior), or lig. sacro-tubcrosum, is formed of several layers 
enclosing fat and muscle. It rises by a broad base from the posterior 
inferior spine and from a little of the adjoining iliac crest, from the 
fourth and fifth articular processes of the sacrum, the free lateral margin 
of that bone, and of the two upper coccygeal vertebrae. It passes down, 
out, and forward, becomes narrow and thick in the middle, and is in- 
serted into the inner margin of the tuber ischii ; thence it is prolonged 
forward as the falciform ligament, forming a groove with the bone for 
the internal pudic vessels and nerve. Some fibres of this ligament 
pass to the tendon of the biceps and semitendinosus : others from the 
posterior superior spine of the ilium pass straight down to the rudiment- 
ary transverse processes of the third, fourth, and fifth sacral vertebrae. 

(4) The small sacro-sciatic ligament (anterior), lig. sacro-spinosum, is 
triangular and attached by its apex to the posterior surface of the spine 
of the ischium and by its base to the free lateral margin of the sacrum 
and upper coccygeal vertebra) : it is attached posteriorly to the great 
ligament, and forms the inferior boundary of the great sacro-sciatic fora- 
men and upper boundary of the small foramen. It should hardly be 
called a ligament, as it is so intimately connected with the coccygeus 
muscle : ligamentous and muscular fibres cross each other at acute angles, 
and sometimes the ligament is almost wholly muscular. 

A superior sacro-spiuous ligament has been seen, forming a middle sacro- 
sciatic foramen. 

The 'great sciatic notch is partly filled by the pyriformis muscle: above 
this pass the gluteal vessels and superior gluteal nerve, and below it the 



THE HIP- JOINT. 123 

sciatic vessels and nerve, internal pudic vessels and nerve, and muscular 

branches of the sacral plexus. 

The small foramen transmits the tendon of the obturator internus 
muscle, its nerve, the internal pudic vessels and nerve. 

THE HIP-JOINT. 
Describe the hip-joint. 

It is a ball-and-socket joint, with arcs of * inch (22 mm. ) radius : 
the radius of the circular edge of the acetabulum is about ^t inch (2 
nun. ) smaller than that of the head of the femur. The articular sur- 
face of the head of the femur is more than a hemisphere : any section 
of the bony acetabulum through its centre is less than 180°. 

The ligaments are — cotyloid, transverse, tens, capsular ; accessor!/ are — 
orbicular zone, Uio-femoraL ilio-trochaiiferic, pubo-femoral, isc It io -femoral, 
and iscii io-capsular. 

The cotyloid consists of connective tissue arranged circularly: it is 
strengthened and fastened to the edge of the acetabulum by short fibres 
rising at different points and interlacing at acute angles. It is prismoid 
on section, and embraces the head of the femur so tightly that air docs 
not enter the joint. Both its sides are covered with synovial membrane. 
Interiorly the cotyloid becomes flat and bridges over the acetabular notch 
as the transverse ligament; it turns one surface upward and one down; 
one edge looks within and limits a split through which, enveloped in fat, 
blood-vessels enter the socket ; the other edge passes uninterruptedly 
into the cotyloid ligament. 

The articular cartilage of the acetabulum is 2 mm. thick, a little thinner 
toward the centre; that on the head of the femur is thickest at the 
centre, i inch (4 mm.). The fossa acetabuli contains a fat pad. 

The lie/amentum teres is misnamed, being neither ligamentous nor 
round; it is somewhat triangular. It is planted by its apex into the 
fossa on the posterior inferior quadrant of the head of the femur, and 
rises from the notch and fossa acetabuli. Unoccupied space around it 
is filled with synovia. _ A cross-section of it discloses an outer firm and 
an inner loose part : it is made up of transverse fibres limited by the 
transverse ligament and longitudinal fibres, which rise from the acetabular 
fossa, and some pass in from the capsule under the. transverse ligament- 
Its function may be (1) to check movement; (2) a remnant from lower 
animals; (3) to carry synovia and vessels (this is most probable). The 
motion it checks is a most unnatural one — viz. is tense with thigh flexed, 
adducted, and rotated in. Sometimes it is a mere synovial fold, and 
sometimes is wanting. 

The capsule springs from the outer surface of the base of the cotyloid, 
from the edge of the acetabulum and margin of the transverse ligament; 
below it is attached to the anterior intertrochanteric line and to the back 
of the neck of the femur in a line parallel to the posterior intertrochanteric 
and about J inch above it. The digital fossa is outside the capsule : it is im- 



124 ARTICULATIONS OF THE LOWER EXTREMITY. 

possible to have a true extracapsular fracture of the neck of the femur. 
At the attachment to bone the innermost layer of the capsule is reflected 
in smooth or longitudinal folds (retinacula) up the neck to the articu- 
lar cartilage of the head, with which it fuses. This layer of the cap- 
sule lined by epithelium is a thin but firm membrane, seen by the 
microscope to be formed of parallel, transverse, or circular bands; 
outside this are connective-tissue layers separating it from the acces- 
sory bands. 

The accessory ligaments are either circular or longitudinal. The cir- 
cular bands form the zona orbicularis, which is most distinct on the under 
wall of the capsule, because less covered here by the longitudinal bands. 
It occupies the middle third of the capsule, and continues upon the upper 
and lower thirds as transverse or scattering bands of connective tissue. 

The accessory longitudinal bands spring from each of the three bones 
forming the acetabulum, and are only lacking in that part of the capsule 
which rises from the transverse ligament. They go between the circular 
fibres, over them, or end in them. 

The ilio-femoral ligament extends obliquely across the front of the 
capsule, attached above to the lower part of the anterior inferior spine, 
and from a point behind this, just above the acetabulum, and below to 
the whole length of the anterior intertrochanteric line. It is covered by 
a fine layer of circular fibres, and pierced by some fibres of origin of the 
outer head of the rectus femoris. At its insertion it is divided into two 
bands — one to the lower part of the line and base of the small trochan- 
ter, and one to the upper part. Sometimes it does not divide, form- 
ing then a triangular band. It is called the inverted ^-ligament of 
Bigelow and lig. of Bertin. It is of great importance in maintaining 
the erect position of the body, and requires 250 to 750 pounds for its 
rupture. 

The ilio-trochanteric ligament rises from beneath the anterior inferior 
spine, and may be considered as the upper arm of the Y-ligament or as 
fibres parallel to it, and inserted into the anterior part of the base of the 
great trochanter. 

The pubo-femorai ligament may be described in three parts at its 
origin : the first is a continuation of the fascia over the pectineus muscle, 
and goes from the ilio-pectineal eminence down between the ilio-psoas 
and pectineus muscles to the lowest part of the capsule ; a second fascic- 
ulus (pubo-femoral of Barkow) comes beneath the pectineus from the 
whole length of the obturator crest, and joins the first set outside that 
muscle ; a third set comes from the upper ramus of the pubis and upper 
obturator spine and joins the others : it gives origin to some fibres of the 
obturator externus. 

The ischiOrcapsular ligament rises from the lower part of the edge of 
the acetabulum and neighboring portion of the ischium, and ends in the 
lower and outer portion of the orbicular zone. 

The ischio-femoral ligament (Macalister) rises from the upper part of 
the ischial tuberosity, passes over the groove between this tuberosity and 



THE KNEE-JOINT. 125 

the acetabulum, and is attached to the back of the neck at a point mid- 
way between the two trochanters. It is often fused with the capsule. 

Synovial processes occupy the joint outside the nitty pad of the fossa 
acetahuli and in the region of the neck of the femur: broad flaps hang 
from the capsular covering of the neck, or thin tufts give a velvety ap- 
pearance to the inner surface of the capsule. 

The ilio-psoas bursa opens into the joint anteriorly, and is analogous 
to the subscapular bursa of the shoulder : it may act as an accessory 
pouch for synovial supply as needed. Where the capsule is thin, mus- 
cles strengthen it: in front is the ilio-psoas; above, the rectus and 
gluteus minimus; internally, the obturator externus and pectineus; 
behind, the pyriformis, two obturators, two gemelli, and quadratus 
femoris. 

Nerves are from the sacral plexus, great sciatic, nerve to quad. fern, 
muscle, obturator, accessory obturator, and anterior crural. 

The arteries are from the obturator, sciatic, gluteal, internal and ex- 
ternal circumflex. 

Movements are in every possible direction. Flexion and extension pass 
through 139° on the dead subject, about 86° on the living ; ab- or adduc- 
tion through 90°, and rotation through 51°. Flexion is checked by soft 
parts and by hamstring muscles (with knee extended), by posterior 
part of capsule and ischio-capsular ligament ; extension is checked by the 
anterior part of the capsule and ilio-femoral ligament ; rotation out, by 
upper arm of ilio-femoral; rotation in, by ischio-capsular and ischio- 
femoral ligaments; abduction, by pubo-femoral lig. and lower and inner 
parts of capsule and impact of head of femur ; adduction, by upper 
arm of Y-ligament, by ilio-troehanteric lig. , and by soft parts. 
_ Ilio-femoral lig. checks extension and tendency to tip backward, rota- 
tion out, and adduction. Pubo-femoral checks abduction. Ischiofemo- 
ral checks rotation in, extraordinary flexion. 

THE KNEE-JOINT. 

Describe the knee-joint. 

This is a double condylar joint, really consisting of three articulations, 
one between each condyle and the tibia, one between the patella and 
femur. _ The lig. mucosum indicates the original separation of the syno- 
vial sac into two. 

The ligaments are — 

Accessory. 

External semilunar cartilage. Anterior : 

Internal semilunar cartilage. Fascia lata. 

Coronpy. Lig. patellae. 

Anterior crucial. Lateral patellar ligaments. 

Posterior crucial. Transverse. 

Capsular. Posterior : 

Ligg. alaria. Popliteal oblique. 



126 ARTICULATIONS OF THE LOWER EXTREMITY. 

Lig. mucosum. Popliteal arcuate. 

Retinaculum or short ext. late- 
ral. 
External : 

External lateral. 
Internal : 

Long internal lateral. 
Short internal lateral. 

The bones are covered with hyaline cartilage to the average depth of 
^ inch (4 mm.). On the anterior part of the condylar surface is a trans- 
verse groove caused by the indentation of the fibro-cartilages : the part 
above this groove articulates with the patella, The free posterior part 
of the condyle corresponds to a radius of § inch (17 mm.). 

The joint-surface of the tibia is much natter than that of the femur, 
and the disproportion is made up by the internal and external semilunar 
fibro-cartilages (meniscus medialis and lateralis). Their upper surfaces 
are concave, their outer edges ^ inch (6 mm.) high, and lower surfaces flat. 
These ligaments are composed of horizontally arched fibres : near their 
outer edges they split into two layers, between which run nutrient vessels. 
Their upper surfaces are covered with a strong fibro-cartilaginous mem- 
brane 1 mm. thick. 

The external cartilage is nearly circular, its anterior extremity being 
inserted in front of the spine of the tibia and its posterior into both the 
inner and outer peak of the spine. The width of this cartilage is about 
| inch (13 mm.). 

The internal cartilage forms nearly a half-circle, and is elongated from 
before backward. Its anterior extremity is in front of the anterior cru- 
cial ligament, its posterior extremity in front of the posterior crucial lig- 
ament. This is widest behind, 17 mm., and gets narrower in front. 

Coronary ligaments connect the convex borders of these cartilages to 
the head of the tibia : they are derived in part from the lateral ligaments. 

The crucial ligaments partly form a sagittal partition wall inside the 
joint, making a right and left chamber in its posterior half. They are 
not like the lig. teres, but are remains of original joints. Between them 
is loose connective tissue, sometimes little bursas. They are named from 
their tibial origins. The anterior rises in front of the external meniscus, 
passes, fan-shaped, up, back, and out to the posterior part of the inner 
surface of the external condyle : the fibres rising most externally are in- 
serted most posteriorly. 

The posterior ligament, a little stronger than the anterior, rises from 
the floor of the popliteal notch on the tibia, and passes up and forward 
to the anterior part of the outer surface of the inner condyle — I e. to the 
inner wall of the intercondylar fossa of the femur : this crosses behind the 
anterior one, forming an X, and its posterior surface becomes external. 

The crucial ligaments receive fibres from the semilunar cartilages, 
rarely any from the inner to the anterior ligament : some pass from the 



THE KNEE-JOINT. 127 

posterior end of the external semilunar to the posterior crucial (third 
erucial), either to its posterior or its anterior surface, or they surround it. 

The capsule of the joint rises anteriorly to a point on the femur § inch 
to 3 inches (1.5 to 8 cm.) above its articular surface ; thence it slopes to 
the epicondyles ; posteriorly it is attached just above the condyles and to 
a line between them and to the gastrocnemius and popliteus. On the 
anterior surface of the femur it is underlaid with rich masses of fat : on 
the patella it is attached close to the edgesof its posterior surface, and 
on the tibia close beneath the articular cartilages, and is connected with 
the origin of the post-crucial lig. 

Anteriorly, above the patella, the capsule is united with the extensor 
tendon : befow this and the patella it is continued as a broad roll to the 
tibia, stretched in flexion, and in extension drawn forward by a special 
muscle. On the sides the capsule is united to the circumference of the 
semilunar cartilages : it presents two layers — one of vertical connective- 
tissue fibres to the edges of the cartilages, and an inner smooth vascular 
layer covering their upper surfaces : this also covers the crucial ligaments, 
so that really the semilunar cartilages and crucial ligaments are outside 
the sac of the capsule. 

Synovial Bursee and Ligaments. — By the semilunar cartilages is the 
joint divided into an upper and lower chamber, and by the crucial liga- 
ments is each chamber divided into lateral halves : into one or other of 
these cavities the subcrural synovial pouch opens. There is a constant 
communication with the popliteal bursa, which is between the popliteus 
muscle and the posterior wall of the lower and outer chamber of the 
joint. In 1 out of 80 cases there is a communication with the upper 
tibio-fibular joint. The groove for the popliteus is covered with carti- 
lage which is continuous with that of the upper tibio-fibular joint. The 
openings from the joint into the subcrural pouch are various in number 
and position, or, most rarely, are absent. 

The bursa semimembranosa lies between the external surface of the 
semimembranosus tendon and the inner head of the gastrocnemius : it 
is about 2 inches (5 cm.) lopg, sometimes simple and sometimes split by 
septa. It communicates with the knee-joint in about one-half the cases, 
more often with the right knee, and more often in robust subjects, and 
never in children. 

The knee-joint contains large fatty synovial folds and tufts :_ the most 
constant are the ligamenta alaria (plica synov. patellaris), which is sep- 
arated in front from the capsule by a mass of fat, and rises up behind 
the articular surface of the patella to near its upper edge. By the ver- 
tical ridge on the posterior patellar surface it is divided more or less into 
its twoNvings (alae) : its upper edge is concave and unites with the lat- 
eral edges of the patella. In flexion of the joint it enters as a pad be- 
tween the patella and tibia. Its position is secured by the lig. mucosum 
(lig. plicae synoy. patellaris), which rises from the bottom of the joint 
and passes free in a sagittal direction through it to the anterior edge of 
the intercondyloid fossa of the femur, rarely attached to the spine of the 



128 ARTICULATIONS OF THE LOWER EXTREMITY. 

tibia or anterior crucial ligament. At its insertion it is usually flat and 
broad, in the middle cylindrical. It may be no larger than a thread. 

Synovial tufts are most numerous on the anterior wall of the joint 
above the patella. Small folds and strings and little follicles of the cap- 
sule lie near its insertion into the tibia. Synovia occupies the spaces not 
filled by synovial folds or fat pads. 

Accessory bands are found upon the anterior, posterior, external, and 
internal walls. 

1. Anteriorly the accessory bands form three layers: (1) The most 
superficial is a continuation of the fascia lata, converging symmetrically 
on either side to be inserted into the tibia or lig. patellae; some pass 
horizontally in front of the lig. patellae and patella. (2) The middle 
consists of tendons and ligaments around the patella. (3) The deepest 
set is transverse. To the second set, the centre of which is the patella, 
belongs the extensor tendon of the leg and three bands : the lowest is 
the lig. patellae (lig. patellare inf.), £ inch (4 mm.) thick, embracing the 
apex of the patella, and passing down and back to the tubercle of the 
tibia with undiminished size. Between this ligament and the capsule is 
a mass of fat ; between it and the head of the tibia is the subpatellar 
bursa; between it and the tubercle of the tibia is a pretibial bursa. The 
side bands of the patella (lig. patellare laterale and mediale) are thin, 
membranous, and triangular. They rise by their apices from the epi- 
condyles of the femur, and pass forward to the sides of the patella, to 
the posterior surface of the extensor tendon and lig. patellae, often sepa- 
rated from the capsule by cellular bursae. The deepest set forms the 
transverse ligament, more or less covered with fat, and passing from the 
upper surface of the internal semilunar cartilage near its anterior ex- 
tremity to the anterior convexity of the outer. It is variable, may be 
round or flat, or lacking, or pass from one cartilage into synovial folds. 

2. The posterior capsular wall has a complicated structure due to its 
connection with various muscle tendons. Above the condyles the cap- 
sule is compact, but lower it shows two transverse bands. The oblique 
ligament (posterior lig. of Winslow, PO, Fig. 13) is a part of the ten- 
dinous insertion of the semimembranosus. This muscle divides into 
four parts at its insertion — one to the front of the tibia in an arched di- 
rection, one straight down to the tibia, one to the popliteal fascia, and 
one on the posterior capsular wall up and out to the outer condyle. 
When the semimembranosus tendon is stretched this oblique ligament 
throws the wall into a fold. 

The arcuate ligament (lig. popliteum arcuatum, pa) is composed of 
arched fibres, concave upward, springing from the external epicondyle 
and losing themselves on the capsule below the oblique ligament. This 
helps form the opening by which the popliteal bursa communicates with 
the joint. To the lower edge of this ligament are inserted a ligament 
and a muscle ; the ligament rises from near the apex of the head of the 
fibula between the biceps and soleus, and spreads its fibres upon both 
sides of the arcuate ligament. It is the retinaculum lig. arcuati (r) or 



THE KNEE-JOINT. 



129 



short externa] lateral ligament. The muscle rising from the arcuate is 
the inner half of the popliteus. When the knee is extended the reti- 
naculum is stretched and the arcuate ligament kept convex: in the flexed 

Fig. 13. 



ADD MAC 



SEMJMEMB 



SHORT INTU 



SEMIMEM 



SEMJMEMB 




PLANTARIS 



GASTROCNEMIUS 



EXT. LAT.L1C. 



[SHORT EXT 

\L at.ug 



BICEPS 



SOLEUS. 



Posterior Surface of Knee-joint. 



position the popliteus does the same, so that the ligament is tense in 
either case, and the canal held open by which the popliteal bursa com- 
municates with the joint. 

3. Externally is the long ext. lateral ligament (lig. accessorium laterale), 
a flat strand separated from the capsule by fat. It rises from the exter- 
nal epicondyle, receiving some fibres from the external intermuscular 
septum, and passes straight to the head of the fibula, spliting the biceps 
tendon at its insertion. The most anterior fibres of this ligament bend 
at right angles to the front, and are lost on the edge of the external semi- 
lunar cartilage : it is tense in extension and relaxed in flexion. 

4. Internally are two ligaments, long and short internal lateral (lig. 
access, mediale longum and breve). Both are from the epicondyle below 
the lateral patellar ligament : the long one is the more superficial and 
attached to the posterior edge of the inner surface of the tibia 2 to 3 
inches (5-8 cm.) below its articular surface. It covers the inferior artic- 
ular vessels and the semimembranosus tendon, and is separated by a 
bursa from the tendons of the gracilis and semitendinosus ; posteriorly 
it becomes very thin. As this rises from about the centre of the circle 

9— A. 



130 



ARTICULATIONS OF THE LOWER EXTREMITY. 



formed by the posterior part of the condyle, it has an equal degree of 
tension in flexion or extension. 

The short internal lateral ligament, placed behind the long internal, 
is a continuation of the semimembranosus fibres vertically to the inner 
semilunar cartilage. 

What bursae are related to the joint ? 

Anterior Bursas. 



Prepatellar. 

1. Subcutaneous. 

2. Subfascial. 

3. Subaponeurotic. 



Pretibial. 

1. One in front of tubercle of 
tibia. 

2. One between lig. patellae and 
tubercle of tibia. 

3. Subpatellar. 



Subcrural Bi 



Externally. 

1. Beneath outer head of gas- 
trocnemius. 
. 2. Beneath tendon of popliteus. 

3. Between tendon of popliteus 
and ext. lat. lig. 

4. Bicipital, between biceps, fib- 
ula, and ext, lat. lig. 



Lateral Bursas. 

Internally. 

1. Beneath inner head of gas- 
trocnemius. 

2. Beneath semimembranosus. 

3. Between semimembranosus 
and semitendinosus. 



The nerves are from the obturator, anterior crural, by branches to the 
vastus externus, internus, and crureus, external and internal popliteal, 
three branches from each, and sometimes the great sciatic. 

The arteries are — the anastomotica magna of femoral, five articular of 
popliteal, recurrent anterior tibial, posterior tibial recurrent, and a de- 
scending branch from the external circumflex. 

Movements to be considered are those between each condyle and tibia, 
between femur and patella. It is a hinge, and owes its special motions 
to peculiarity of ligaments rather than to conformation of bone, as in 
case of elbow. Flexion and extension have a maximum of 140° : flexion 
is arrested mostly by the anterior crucial ligament ; the anterior fibres 
of the posterior ligament are also stretched. At the beginning of flexion 
both crucial ligaments become relaxed : both are stretched in extension, 
especially the posterior short fibres of the posterior crucial. In exten- 
sion the lateral ligaments are tense, and do not allow any motion but 
flexion. Flexion and extension do not occur in a pure hinge-like man- 
ner: the same part of one articular surface is not always applied to the 
same part of another ; the axis of motion is not a fixed one. The motion 



LIGAMENTS BETWEEN THE RONES OF THE LEG. 131 

of the femur on the tibia is likened to that of a carriage-wheel on the 
ground: it advances or recedes while* it rotates. 

The semilunar cartilages are loosely attached, and move forward in ex- 
tension and backward in flexion of the joint like movable wedges ; as the 
condyles roll and present different curvatures, each cartilage contracts or 
expands to fit the surface above. The actual contact of the femur with 
the tibia is hardly more than linear. 

In extension the anterior capsular wall is raised by the subcrural mus- 
cle ; in flexion the posterior wall has two muscles to prevent its bulging 
into the joint. The semimembranosus acts through its oblique ligament 
when the flexors from the thigh and pelvis are in operation ; the popli- 
teus, through the arcuate ligament when the plantaris and those at- 
tached to the os calcis act. 

As flexion increases, rotation is possible, and increases to a total of 
39°, dueto a relaxation of lateral and crucial ligaments. Rotation out 
(supination) is most extensive, as the external lateral ligaments are more 
loose than the internal ; this occurs on an axis through the inner condyle 
and inner tuberosity of the tibia. This motion is checked by the internal 
lateral ligament and the winding of the posterior crucial around the spine 
of the tibia. Rotation in (pronation) on an axis through the outer con- 
dyle and outer tuberosity of the tibia is never more than 5° or 10°; this 
motion is checked by the anterior crucial ligament and by the twisting of 
these crucial ligaments around each other. 

At the close of full extension there is a movement of adaptation, or 
gliding back of the inner condyle upon the tibia : this axis is through the 
external condyle. At the beginning of flexion a reverse motion takes 
place. 

The movements of the patella are partly gliding and partly those of co- 
aptation. ( In extension only the lower one-sixth of the patellar articular 
surface is in contact with the femur ; in semiflexion, the middle three- 
sixths ; in full flexion, the upper two-sixths, as the lig. patellae pulls it 
down in front of the joint. 

LIGAMENTS BETWEEN THE BONES OF THE LEG-. 
Describe the ligaments between the bones of the leg. 

In the upper tibio-fibidar articulation is a capsule and two accessory 
bands. 

The capsule rises from the tibia about ^ inch (5 mm. ) above the artic- 
ular surface, elsewhere from its edge; it passes to the contiguous mar- 
gins of the fibular surface, and generally encloses a little space at the 
lower part of the joint, covered only by periosteum, where the tibia and 
fibula rest upon each other. 

Accessory bands are anterior and posterior ligaments (lig. capituli 
fibulae ant. and post.). The former consists of one or more bands from 
the front of the head of the fibula to the front of the outer tuberosity 
of the tibia : some fibres of the peroneus longus and extensor long, digit. 



132 ARTICULATIONS OF THE LOWER EXTREMITY. 

rise from it. The posterior ligament connects the bones in a similar 
manner, and is covered by one head of the solens. This joint-cavity 
may communicate with the knee-joint. Fat fills the space between the 
capsule and interosseous membrane. 

The joint-surfaces move in a transverse and sagittal direction, more in 
the former; the purpose of the movement is to allow a gliding at the 
lower ends of the bones. 

Between the bones is the interosseous ligament or membrane, its fibres 
passing down and out to the fibula ; it separates the flexor from the ex- 
tensor muscles. Above is an opening for the anterior tibial vessels, and 
below another for the anterior peroneal. Close to the upper tibio-fibular 
joint is a band of fibres analogous to the oblique ligament of the fore- 
arm, running in a direction opposite to the fibres of the rest of the mem- 
brane. If the forearm be pronated and compared with the leg, the two 
interosseous ligaments run in parallel directions. 

The inferior tibio-fibular joint presents interosseous, anterior, posterior, 
and transverse ligaments. The interosseous is continuous with the inter- 
osseous membrane above. The anterior and posterior ligaments connect 
corresponding surfaces of the two bones. The transverse is under the 
posterior ligament, projects below and connects the margins of the bones, 
and forms part of the articulating surface for the astragalus. 

THE ANKLE-JOINT. 
Describe the ligaments of the ankle-joint. 

The ligaments are anterior, posterior, internal lateral, and external 
lateral. 

The anterior is broad and thin, and connects the tibia and astragalus. 
The posterior consists mostly of transverse fibres between the tibia and 
astragalus. 

The internal lateral or deltoid has a superficial and a deep layer: the 
former rises from the apex, anterior and posterior borders of the internal 
malleolus, and passes forward to the scaphoid and inferior calcaneo- 
scaphoid ligament, downward to the posterior edge of the sustentaculum 
tali, and backward to the astragalus, all to different bones ; the deep layer 
is strong and thick, and passes from the apex of the malleolus directly to 
the inner surface of the astragalus. 

The external lateral ligament has three fasciculi — one from the ante- 
rior part of the external malleolus to the astragalus, a middle one from 
the apex of the malleolus to the os calcis, and a posterior one from the 
back of the malleolus to the astragalus. (For movements, etc. see p. 
137.) 

JOINTS OF THE FOOT. 
What are the ligaments of the tarsus ? 

There are three sets — articulations of first row, of second row, of the 
two rows with each other. 



JOINTS OF THE FOOT. 133 

Those <>l' the first row, between the astragalus and os calcis, are exter- 
nal^ internal, and posterior calcaneo-astragaloid and interosseous. The 
external is in front of and parallel with the middle fasciculus of the ext. 

lat. lig. : it is inconstant and connects the outer surfaces of the two 
bones. The internal passes from the inner tubercle of the astragalus 
to the sustentaculum tali. The posterior is narrow and connects the 
posterior borders of the two hones. The interosseous is thick and strong 
and tills the groove between the two hones. 

The ligaments of the second row are dorsal, plantar, and four inter- 
osseous. These include the scapho-cuboid ligaments. 

The ligaments connecting the two rows are of three sets — viz. (1) be- 
tween os calcis and cuboid ; (2) between os calcis and scaphoid ; (3) be- 
tween astragalus and scaphoid. 

(1) Superior, Internal, Long and Short Calcaneo-cuboid. — Thesuj)<r/<>r 
connects the upper surfaces of the two bones. The internal is some- 
what interosseous. The long plantar (long calcaneo-cuboid) passes from 
the tuberosities of the os calcis to the ridge on the under surface of the 
cuboid, completing a canal for the peroneus long, tendon. 

The short plantar extends from the anterior tubercle of the os calcis 
to the cuboid behind its peroneal groove. 

{2) The ligaments are superior and inferior ealcaneo-scaphoid. The 
superior and internal calcaneo-cuboid form the arms of a Y. 

The inferior passes from the sustentaculum tali to the tuberosity of 
the scaphoid, forming an articular cavity for the head of the astragalus: 
it is supported below by the tibialis posticus tendon. 

(3) There is a thin superior astragalo-scaplioid ligament : an inferior 
ligament is supplied by the inferior calcaneo-scaphoid. 

What are the remaining ligaments of the foot ? 

Tarso-metatarsal joints have dorsed, plantar, and interosseous liga- 
ments : the latter are three in number. 

The intermetatarsal articulations have dorsal, plantar, and interosseous 
ligaments : the digital extremities are united by a transverse metatarsal 
ligament which connects the great toe to the others. 

Metatarso-phalangeal and interphalangeal articulations have each 
plantar and tioo lateral ligaments. 



HENLE'S CLASSIFICATION OF THE ANKLE- AND FOOT- 
JOINTS. 

The articulations of the ankle, tarsus, etc. are all described under one head, 
the "foot-joints." 

A division into capsular membranes and accessory bands cannot here be 
made just as in the hand : a ligament may pass over more than two bones, or 
one connecting two bones may help form a joint-socket. There are three dis- 
tinct movable joints to be considered— that of the ankle, the anterior and 
posterior astragaloid joints: all the others are amphiarthrodial. 



134 ARTICULATIONS OF THE LOWER EXTREMITY. 

A. Lower Tibio-fibuhir Joint. 

A thin capsule is mentioned. The interosseous ligament (membrane) ceases 
f t inch (10 mm.) above the lower extremity of the tibia: this distance between 
the tibia and fibula is a space hardly deserving the name "joint-cavity." The 
tibial surface is covered with periosteum, the fibular with a flat pad of fat 
i " valved pad") interposed in the chink between the bones. This allows a 
"give" in the joint: it is squeezed up between the bones and articulates be- 
low with the supero-external border of the astragalus, and prevents that bone 
from being pushed up between the tibia and fibula. 

Accessor)/ bands, anterior and posterior (lig. malleoli lateralis ant. and lig. 
mal. lat. post.), are continuous above with the interosseous ligament and be- 
low with the puffy edge of the capsule of the ankle. The anterior band is 
triangular, and passes down and out from the tibia in front of its articular 
surface to a corresponding point on the fibula. Anteriorly it is covered with 
fat and loose connective tissue: its posterior surface is in the ankle-joint, and 
its lower edge overhangs the astragalus. 

The posterior ligament resembles the anterior in shape, but is stronger; rises 
not only from the posterior surfaces of the two bones, but also from their op- 
posing surfaces and from a deep fossa behind the articular surface of the fib- 
ula. These lowest fibres (transverse lig. of Gray) run to the inner malleolus 
of the tibia or are lost on its posterior capsular wall. Both accessory bauds 
are tense iu flexion of the foot and relaxed in extension. 

B. Joints of the Astragalus. 

Capsular Ligaments. — 1. Talo-crural Articulation. — Talus = astragalus, os navic- 
ulare = scaphoid. Surfaces are covered with hyaline cartilage 1 to 2 mm. thick ; 
the accessory bands of the lower tibio-fibular joint help form these joint sur- 
faces. The upper articular surface of the astragalus corresponds to a radius of 
$ inch (l7to 21 mm.) and an arc of 120°; the extent of articular surface on 
the tibia is related to that on the astragalus as 2 : 3. Both head and socket di- 
minish in a transverse direction toward the posterior from 32 to 28 mm. The 
capsule is tense on the sides and loose anteriorly and posteriorly, where it is 
thrown alternately into folds in flexion or extension : it is attached close to 
the articular surfaces except in front of that on the astragalus, where it en- 
closes a rough space covered partly by fat and partly by thin periosteum. 
Vertical septa divide this little anterior pouch into compartments which com- 
municate with the general cavity only by narrow mouths. On the posterior 
capsular wall are hernia-like protrusions. The strengthening fibres on the 
posterior wall pass down and in ; on the anterior wall down and out. Thick 
fat pads lie upon the anterior and posterior capsular walls : the posterior is 
enclosed in fascia to which the plantaris is attached, so that this pad and the 
capsule are pulled back when that muscle contracts. 

2. Posterior Astragalus Joint (astragalo-calcanea). — Thesurface on the os calcis 
is that of a cylinder of l£ inches (28 mm.) radius, whose axis passes from the 
posterior edge of the outer surface of the bone to the anteroinferior edge of 
the inner, making an angle of 30° with the long axis of the foot. The head 
of the joint is on the calcaneum, the socket in the astragalus; and motion 
here is a rotation of the foot on its long axis. The capsular membrane is close 
to the articular surfaces iu the region of the interosseous groove, elsewhere is 
farther away : it is in relation to fatty masses, especially so near the canalis 
tarsi. 

3. Anterior Astragalus Joint (astragalo-calcaneo-scaphoidea). — This is a joint 
of cylindrical surfaces: the head includes the anterior surfaces of the astrag- 



JOINTS OF THE FOOT. 135 

alus and the anterior part of its lower surface: the socket is made of the in- 
ner articular surface of the OS calcis, the posterior surface of the scaphoid, and 
the lig. tibio-calcaneo-iiaviculare (inferior calcaneo-scaphoid), and its fibro- 
cartilage. A horizontal section of the head shows an arc of 120°; a vertical 
section is a little smaller. The lig. tibio-calcaneo-navictilare tills up the space 
in the plantar arch on the inner edge of the foot between the scaphoid and 
os calcis: it is made up of fibres which pass forward from the groove on the 
astragalus for the flex. long. poll, tendon, fibres passing down and forward 
from the tip of the inner malleolus, down and hack from the scaphoid, up 
and forward from the sustentaculum tali. At the junction of all these fibres 
there is an elliptical ligamentous disk | inch (6 mm.) thick, hard like car- 
tilage, and may he ossified in spots. This supports the head of the astragalus, 
preserves the arch of the foot, and forms a groove for the tibialis posticus 
tendon. 

The socket of this joint presents three zones : (1) corresponds to the postero- 
internal articular surface on the sustentaculum tali; (2) divided also into 
three parts, (2') the antero-internal articular surface on the calcaneum, (2") 
the lig. tibio-calc.-naviculare, (2'") the ligamentous disk of this ligament; 
the third (3) zone is the anterior wall of the socket and belongs to the sca- 
phoid. All these bony surfaces are marked off" by deep furrows and fatty 
synovial folds. The joint-head also presents three zones nearly corresponding 
to the above. 

The capsule of this joint springs inferiorly close from the edges of the artic- 
ular surfaces, superiorly at some distance from the edges, and internally it 
reaches uuder the tibio-calc.-navic. lig. close to the ankle-joint. 

Accessory Ligaments. — Of the astragalus joints there are three groups: (1) 
those connecting the astragalus with the bones of the leg ; (2) those connect- 
ing the astragalus and os calcis ; (3) that between the astragalus and scaphoid. 
The external are usually longer and stronger than the internal. 

I. Ligg. Talo-cruralia. — These pass two from each malleolus obliquely down 
to the astragalus, one backward and one forward on each side. They hold 
the astragalus so firmly under the tibia that no rotation about a sagittal axis 
is possible. By flexion of the foot the two posterior are stretched, by exten- 
sion the two anterior. 

1. Lig. Talo-fibulare Posticum, the posterior fasciculus of the ext. lat. of 
Gray ; origin, fossa on fibula behind its articular surface ; insertion, posterior 
surface of astragalus near the outer tubercle of the flex. long. poll, groove. 

2. Lig. Talo-tibiale Posticum (posterior superficial fibres of deltoid), from 
a little fossa behind the tip of inner malleolus to a smooth place on the astrag- 
alus below the posterior half of the joint-surface. 

3. Lig. Talo-fibulare Ant. (anterior fasciculus of ext. lat. lig.), external 
malleolus to astragalus, 10 mm. broad; may divide into two at its insertion. 

4. Lig. Talo-tibiale Ant. — Short band, 3 mm. broad, deeply placed under 
other ligaments; passes from apex of inner malleolus to a point behind the 
rounded apex of the inner joint-surface of the astragalus. 

II. Ligg. Talo-calcanea. — 1. Lig. Talo- calcaneum Posticum springs by a point 
from the outer tubercle of the flex. long. poll, groove, and is inserted broadly 
or by two arms into the upper and inner surface of the os calcis. 

2. Lig. Talo-calcaneum Laterale. — Ext. calc.-astragaloid of Gray ; from upper 
and outer surface of os calcis, covered by the short extensor muscle, passing 
through the fat at the entrance of the sinus tarsi, upward, inward, and back- 
ward to the rounded margin of the astragalus, which overlies the canalis tar- 
si. It is frequently doubled and frequently lacking. 

3. Lig. Talo-calcaneum Mediale, a small nearly horizontal slip from the inner 



136 ARTICULATIONS OF THE LOWER EXTREMITY. 

margin of the flex. long. poll, groove to the posterior edge of the sustentaculum 
tali. 

4. Lig. Talo-calcaneum Interosseam (interosseous calcaneo-astragaloid). — This 
fills the tarsal canal; consists of several layers and mostly short fibres. In 
the narrowest part of the canal two layers cross each other obliquely. 

III. Lig. Talo-naviculare are dorsal fibres between the neck of the astragalus 
and middle of the scaphoid : it has two parts, which lie beside each other on 
the astragalus and overlap on the scaphoid, the external lying upon the inner 
ones, and some going on to the middle cuneiform. 

IV. Long Accessory Bands between Bones of the Leg and Tarsus. — 1. Lig. Tibio- 
naviculare (ant. superficial fibres of deltoid), from the anterior edge of inner 
malleolus down and out to the dorsum of the scaphoid. 

2. Lig. Calcaneo-fibulare (middle fasciculus of ext. lat. lig.), from the apex 
of the external malleolus to a little tubercle in the middle of the external 
surface of the os calcis : it is covered by smooth membrane and helps form a 
groove for the peroneal tendons : it may be doubled. 

3. Lig. Calcaneo-tibiale (middle superficial fibres of deltoid), from inner 
malleolus to posterior edge of sustentaculum tali. 

C. Amphiarthrodia of Tarsus. 

First row = astragalus and os calcis ; second row = scaphoid and posterior half of 
cuboid ; third row= the cuneiform bones and anterior half of cuboid. 

Capsular membranes are variable in number, but should be nine; they are 
tense, and grow close to the edges of the joint-surfaces. The synovial folds 
are fatty and small. There is a capsule for (1) the calcaneo-cuboid joint; (2) 
the cuneo-navicular, which also includes the articulations of the cuneiform 
with each other, the external cuneiform with the cuboid, the navicular with 
the cuboid (sometimes) ; (3) tarso-metatarsal joints: capsules usually three in 
number— one for the internal cuneiform and first metatarsal, one for the mid- 
dle and external cuneiform and second and third metatarsals, the third for 
the cuboid and fourth and fifth metatarsals. 

Accessory Bands of Tarsus. — I. On Dorsal Surface. — 1. Transverse : (a) in sec- 
ond row, ligg. naviculari-cuboidea, a superficial and a deep one; {b) in third 
row, (1) ligg. cuneo-cuboid., an anterior and a posterior one; (2) between second 
and third cuneiforms; (3) between second and first, (c) In the metatarsus, 
ligg. intermetatarsea dorsalia, lacking between the first and second. 

2. Sagittal : (a) between first and second rows, (1) lig. calcaneo-navicularcdorsale 
= superior calcaneo-scaphoid ; (2) ligg. calcaneo-cuboidea dorsalia, two or three 
bands = superior and internal calcaneo-cuboid; (b) between second and third 
rows, (1) between scaphoid and outer cuneiform; (2) scaphoid and middle 
cuneiform, two bands; (3) scaphoid and inner cuneiform, two strong bands; 
(c) between third row and metatarsus, ligg. tarso-metatarsea dorsalia; one to 
the first metatarsal from the internal cuneiform ; three to the second, one 
from each cuneiform ; to the third are variable bands, may be two from the 
two outer cuneiform ; to the fourth, one, sometimes two, from the cuboid ; to 
the fifth, one from the cuboid. 

II. Accessory Bands of Plantar Surface. — There are long bands which are 
superficial and pass over several bones ; short bands which are deep and con- 
nect adjoining bones, (a) Long Ligaments. — Lig. calcaneo-cuboideum plantarc = 
plantar ligaments of Gray. This rises from the whole rough under surface 
of the os calcis from the two posterior tubercles to the anterior one: it is 
divisible into three layers. The most superficial passes over the tuberosity 
of the cuboid to the flexor brevis poll, muscle, to the interossei and bases of 
the metatarsal. These last fibres are strengthened by single bundles rising 



JOINTS OF THE FOOT. 137 

from the tuberosity of the cuboid: the fibres to the flexor brevis poll, are 
joined by transverse fibres from the tendon of the tibialis posticus, and are 
also connected with the plantar fascia. 

The middle set of fibres extends to the tuberosity of the cuboid. The 
deepest set is inserted into the cuboid behind its tuberosity, passing mostly 
from the anterior tubercle of the os calcis : it comes to view internal to the 
upper layers. 

The Hi;. tarseum transversum laterale goes from the external cuneiform, cov- 
ered by the peroneus longus tendon, to the tuberosity of the fifth metatarsal. 

The lig. tarseum transversum mediate runs from the inner surface of the inner 
cuneiform to the base of the third, sometimes fourth, metatarsal. 

{b) Short Ligaments. — 1. Transverse: (a) in second TOW,lig.cuboideo-naviculare 
plantare; (6) in third row, between the cuboid and outer cuneiform and be- 
tween the cuneiforms is a continuous band or several separate ones; (c) in the 
metatarsus, ligg. mtermetatarsea plantaria, only between the four outer bones: 
the lack of one between the first and second is supplied by a band from the 
internal cuneiform to the base of the second. 

2. Sagittal: (a) between first and second rows, lig. calcaneo-navieulare plan- 
tare, a short round band running obliquely inward and forward to the navic- 
ular bone from .the anterior inner corner of the os calcis ; (b) between the 
second and third, rows, from the scaphoid to the cuneiforms, a broad band 
covered by the tibialis posticus tendon ; (c) between the third row and meta- 
tarsus, ligg. tarso-metatarsea plantaria, a broad and strong band to the first from 
the inner cuneiform; weak bands to the second from the middle and outer 
cuneiforms; to the third, short bands from the middle and external cunei- 
forms and cuboid ; to the fourth, a band from the outer cuneiform or from 
the cuboid, or from both. 

3. Accessory Bands in the Interspaces of the Metatarsus. — Ligg. mtermetatarsea 
inter ossea lie in the spaces just in front of the capsules in which the side sur- 
faces of the bases of the metatarsals articulate with each other. 

What separate synovial cavities are there? 

Usually six — one for the posterior calcaneo-astragaloid joint; one for the 
anterior and the astragalo-scaphoid joint ; one for the calcaneo-cuboid; one 
for the cuneo-scaphoid, the cuneiform w T ith each other, the external cunei- 
form with the cuboid, the middle and external cuneiform with the second 
and third metatarsals ; one for the first metatarsal and internal cuneiform; 
one for the fourth and fifth and cuboid ; sometimes one between the scaphoid 
and cuboid. 

Nerves for ankle-joint proper are from anterior and posterior tibials : tarsal 
joints have the anterior tibial and plantars. 

Arteries of ankle are anterior and posterior tibials, anterior and posterior 
peroneals; lower down are the plantars and dorsalis pedis. 

The movements of the ankle-joint are flexion and extension — a little lateral 
motion in extension : this is possible because the astragalus and tibio-fibular 
mortise are a little wider in front than behind, and in extension the nar- 
rowest part of the astragalus is in the widest of the articular socket. In 
flexion, as in stepping upon a chair, where lateral motion would be dan- 
gerous, the two joint-surfaces fit closely. With flexion is associated a slight 
rotation out of the foot ; with extension, a slight rotation in. Flexion, a 
lifting of the apex of the foot, is possible to 20° from the horizontal ; exten- 
sion, a depression of the apex of the foot, goes through 45°. 

Eversion or inversion of the foot means a rotation out or in of the whole 
lower extremity. Rotation out or in is rotation of the whole foot on a longi- 



138 MYOLOGY. 

tudinal axis: this occurs at the posterior calcaneo-astragaloid joint. The 
fool is rotated in when the sole looks in. Adduction or abduction refers to a 
displacement in <>r out of the fore-foot, motion occurring in the tarsal joints, 
especially mid-tarsal. 
The movements between the lower ends of the tibia and fibula are those of 

elasticity. 

What are the ligaments of the metatarso-phalangeal joints ? 

Each has a capsule, which is connected with the other by ligg. capitulorum 
plantaria and dorsalia, which together form the transverse metatarsal liga- 
ment of Gray. It connects the great toe with the others. Under tin; joints 
it is developed into a thick fibrous or sesamoid plate. In the one for the great 
toe the plate is ossified into two bones held together by transverse bands: 
this may occur in other toes. Besides the above there are two lateral liga- 
ments. As a rule, there is a bursa between the capsules in the three inner 
intermetatarsal spaces. 

The interphalanyeal articulations are practically the same as those of the 
fingers. 



MYOLOGY. 

How are muscles divided? 
Into— 

I. Voluntary, .striated (animal life) ; 

II. Involuntary (vegetative life) — («) smooth, non-striated, {b) striated 
(cardiac). 

Describe the structure of muscle. 

I. Primitive muscle fibrillce form fibres ; fibres, fasciculi; fasciculi, 
muscles or flesh. 

Epimysium surrounds entire muscle, and sends partitions between fas- 
ciculi, called perimysium ; endomysium is between the fibres, but not as 
a sheath. 

The fibres average 4^ inch in diameter, 1 ] inches long ; by volition 
may contract one-fourth or one-third of its length, by electricity three- 
fourths. They consist of (1) central contractile substance, (2) nuclei. [3) 
tubular sheath or sarcoleinma: they are divisible into the primitive 
fibrillar, shown by longitudinal striations, and each fibrilla breaks into 
disks called sarcous elements, dark in the centre, with a lighter zone at 
each end ; transversely through the light zone passes Xranses Hue, or 
membrane limiting with the sarcolemma each element ; Hensen's line 
passes transversely through the central dark band. 

Striated muscles comprise those of locomotion, respiration, expres- 
sion ; those of ear, larnyx, pharynx, tongue, upper half of oesophagus, 
and walls of large veins near heart. 

II. {a) Smooth, unstriped muscular fibres are made up of long nu- 
cleated cells, collected in bundles or layers, surrounded by connective 
tissue ; the cell-body shows a longitudinal striation. This variety of 



MUSCLES OF THE TRUNK. L39 

muscle is (bund in the lower part of the oesophagus, stomach, intestinal 
canal. Bpleen, trachea, bronchial tubes, gall bladder, bile-duct, duels of 
large glands, of sweat-glands, uterus, appendages, vagina, ureters, blad- 
der, urethra, corpora cavernosa, dartos, epididymis, prostate, ciliary 
muscle, iris, coats of veins, arteries, and lymphatics, (b) Iii striated 
heart-muscle the fibres anastomose and form a long-meshed network ; 
no Barcolemma: transverse striae are weak, fibres small, and made up 
of quadrangular cells joined end to end, each with a central nucleus. 

MUSCLES IN GENERAL. 

They arc symmetrical in pairs, excepting tlie sphincters and a few 
others. They number about 31 1 (voluntary): head and front ofneck = 
82, vertebra] column and back of neck = 60, thorax = 42, abdomen = 14, 
upper limb = 59, lower limb = 54. If a man weighs 150 pounds, his 

skeleton weighs 28 pounds ; muscles, G2 pounds (over 40 per cent. ) ; vis- 
cera, fat, blood, etc., 60 pounds. 

How are muscles named? 

(1) From situation, as tibialis ; (2) direction, rectus ; (3) use, flexors ; (4) 
shape, deltoid; (5) subdivision, biceps; (6) attachment, sterno-cleiclo- 
masto-occipitoid ; (7) size, magnus; (8) bellies, digastric ; (9) structure, 
semimembranosus; (10) relation to organs, extrinsic or intrinsic ; Ml) 
position, superficial or deep ; (12) name of describer, Horner's, Galen's. 

Some muscles are synergists to others, some antagonists, some mode- 
rators. 

The origin of a muscle refers to its more fixed, the insertion to its more 
movable or remote, attachment. The same nerves that supply joints gen- 
erally supply the muscles and integument over those joints. 

How are fasciae arranged? 

The superficial fascia is subcutaneous all over the body: its web con- 
tains subcutaneous fat, the panniculus adiposus, and often superficial 
muscles, the panniculus carnosus. There is no fat in this layer in the 
eyelids, penis, and scrotum. Beneath the fatty layer is usually another, 
devoid of fat, for the support of vessels and nerves. 

The deep fascice or aponeuroses are made of strong fibrous tissue cov- 
ering the body more or less, forming aponeuroses of investment or of in- 
sertion for muscles. Near some joints it is strengthened by transverse 
bands, forming retinacula or annular ligaments to hold tendons close to 
bone. 

MUSCLES OF THE TRUNK. 

MUSCLES AND FASCIiE OF THE BACK. 
Describe the muscles of the back. 

[a) Superficial, running out from spinous processes, 

"irst Layer. — Musculus Trapezius (cucullaris), or hood muscle. — 



fc 



140 MUSCLES OF THE TRUNK. 

Origin, inner third superior curved line of occipital bone, lig. nuchse, 

spinous processes of the seventh cervical, and all the dorsal vertebrae and 
supraspinous ligament; insertion, fibres converge to shoulder girdle; 
superior ones to outer third or half of posterior border of clavicle ; mid- 
dle fibres horizontally to inner margin of acromion and superior lip of 
scapular spine ; inferior fibres up and out to a triangular tendon gliding 
over the inner extremity of the spine and inserted into a tubercle at its 
lower posterior margin. The aponeuroses of the two muscles form an 
ellipse widest at the seventh cervical spine. 

Varieties. — May not rise from lower six dorsal spines ; no occipital attach- 
ment ; separation of cervical and dorsal parts; vestige of pauniculus carnosus 
superficial to it. 

Second Layer. — 1. M. Rhomboideus Minor. — Origin, seventh cer- 
vical and first dorsal spines and lig. nuchse of that region ; insertion, 
base of scapula opposite triangular surface at commencement of spine. 

2. 31. Rhomboideus Major. — Origin, spinous processes of four or five 
upper dorsal vertebne and supraspinous ligament ; insertion, base of 
scapula between spine and inferior angle. The greater part of its fibres 
is not fixed directly to bone, but ends in a tendon attached to the lower 
angle of the scapula, so that the muscle acts more especially upon this 
angle. 

This muscle comes to view in the sixth intercostal space, with the scapula 
external, trapezius internal, and latissimus dorsi below. Variable in verte- 
bral and scapular attachments; the division between the two indistinct. M. 
rhomboideus occipitalis (occipito-scapularis) above rhomb, min. from occiput 
beneath splenitis to scapula, covering insertion of rhomb, min., normal in 
rabbits. 

3. M. Teres Major, not round. — Origin, dorsal aspect inferior angle 
of scapula, slightly from axillary border, from septa between it, the 
minor and infraspinatus, from infraspinatus fascia; insertion, by flat 
tendon, 2 inches wide, behind latissimus dorsi into inner bicipital ridge 
of humerus. The two tendons are united below for a short distance, 
but separated by a bursa at their insertion. 

May be connected with latissimus dorsi where it rises from the scapula; a 
slip to the fascia of the upper arm externally. 

4. M. Latissimus Dorsi, broad and flat at its origin, narrow at its in- 
sertion. — Origin, spinous processes of lower six or seven dorsal ver- 
tebrae, posterior layer of lumbar aponeurosis, which attaches it to the 
lumbar and sacral spines and iliac crest, from external lip of iliac crest 
in front of lumbar aponeurosis; from last three or four ribs by digita- 
tions interposed between those of the external oblique ; usually by a slip 
from inferior angle of scapula. Its upper fibres are nearly horizontal, 
middle, oblique, and lower, vertical : it winds round the ten's major and 
in front of it, and is inst zrted by a tendon U inches wide into floor of bi- 
cipital groove, a little higher than the teres major, and by its upper edge 



MUSCLES AND FASCIAE OF THE BACK. 141 

into the inner lip of the groove limiting the insertion of the subscap- 
ularis. 

Vertebral and costal attachments variable; muscular bands, axiUary arches 
from near the insertion across the greal vessels and nerves to either the great 
pectoral tendon, coraco-brachialis, biceps, or fascia; a slip from lower ribs to 
coracoid= m. costo-coracoid ; a slip to triceps, fascia, or internal intermuscular 
septum = m. dorso-epitrochlearis of apes, usually present in man as a fibrous 
band. 

Third Layer. — Serrati Muscles.— 1. M. Serratus Posticus Superior. 
— Origin, by a thin aponeurosis from two, rarely three, upper dorsal 
spines, supraspinous ligament, seventh cervical spine, lower part of lig. 
nuchas ; fibres pass down and out ; inserted by four slips into the upper 
borders and outer surfaces of the second, third, fourth, and fifth ribs 
beyond their angles. 

The slips may be three or increased to six. 

2. M. Serratus Post. Inferior, broader than the above. — Origin, by 
part of the lumbo-dorsal aponeurosis from first two lumbar and last tw 7 o 
or three dorsal spines ; passing up and out ; inserted by four slips into 
the lower borders of the last four ribs up to the origin of the lat. dorsi. 

Tbe two middle slips are broadest ; the others may be lacking ; they over- 
lap each other from above. 

Fourth Layer. — Mm. Splenii. — Named from strap-like action bind- 
ing down underlying parts ; rise from lower half of neck and upper half 
of back. 

1. M. Splenitis Capitis. — Origin, lig. nuchae over third, fourth, fifth, 
and sixth cervical spines, from seventh cervical and first two dorsal 
spines; insertion, outer surface and posterior margin of mastoid process, 
outer part of superior curved line to insertion of trapezius. 

2. M. Splenius Cervicis (colli). — Origin, below the above from third, 
fourth, fifth dorsal spines, not lower than the sixth ; insertion, w T ith slips 
of levator ang. scap. into tips of trans, proc. of first and second, often 
third, cervical vertebrae. 

The splenii are covered in part by the trapezius, rhomboidei, and superior 
serratus; the complexus comes to view internal to them. The m. rhombo- 
atloideus, or splenius colli access., rises from the lower one or two cervical spines 
superficial to the superior serratus, inserted into the trans, proc. of tbe atlas. 
31. splenius capitis access, is a similar slip ending on the occipital bone or 
mastoid. 

Nerves. — Trapezius by spinal accessory, third and fourth cervical n. ; rhom- 
boidei by fifth cerv. n. ; teres major by lower subscapular n. (6, 7 c.) ; latissi- 
mus dorsi by long subscapular n. (7, 8c); serrati by intercostals or upper slip 
of ser. post. sup. by cervical plexus ; splenii by posterior spinal n. 

Actions. — Trapezius, upper part supports shoulder, raises point of shoulder 
by rotation of scapula, acts in forced respiration ; middle part adducts scap- 
ulse, helps elevate shoulder, throw's chest out; inferior part would alone de- 
press and carry scapulse in, but in concert with the upper two-thirds of the 



142 MUSCLES OF THE TRUNK. 

muscle it raises acromion and carries lower angle out and up. Fixed below, 
one acting, draws head back and rotates face to opposite side; both acting, 
draw head back. The rhomboidei are special antagonists of the serratus mag- 
nus; they elevate the superior angle of the scapula and counteract the rota- 
tion of the trapezius; combined with the trapezius, the scapula is raised 
without rotation or drawn back and in. Teres major, fixed at humerus, 
rotates scapula; fixed at scapula, rotates raised humerus in and depresses 
arm. Latissimus dorsi, fixed at humerus, draws body forward as in using 
crutches or climbing, feebly in forced respiration; fixed below, carries ele- 
vated arm down, back, and rotates in ; draws shoulder down and back ; is 
used in swimming; keeps inferior angle of scapula close to chest-wall. 

Serratus post, sup., muscle of forced inspiration ; serratus post, inf., muscle 
of forced expiration (Quain says of inspiration, as it holds the lower ribs fixed 
when the diaphragm tends to draw them up). 

Splenii of one side draw head and neck back and rotate face to same side ; 
help keep head erect. 

What are the dorsal and lumbar fasciae ? 

The vertebral aponeurosis represents the middle portion of the muscu- 
lar sheet of the serrati ; above, it passes beneath die superior serratus ; 
below, it is blended with the lat. dorsi and inferior serratus, and binds 
down the long extensor muscles. The lumbar aponeurosis is usually 
described in three layers, enclosing the erector spinas and quad, lurubo- 
rum: its posterior layer is continuous with the vertebral aponeurosis, 
and by it the lat. dorsi and inferior serratus are attached to the vertebral 
spines. 

(b) Deep Longitudinal ^ Muscles. —Long Muscles.— 1. 31. Sacro- 
spinal, p. n.* (erector spina?). — Origin, lowest two or three dorsal, all 
the lumbar and sacral spines, posterior fifth of inner lip of iliac crest, 
lower and back part of sacrum, anteriorsurface of lumbar fascia : oppo- 
site the last rib this mass divides into middle and outer columns, and an 
inner one, spinalis dorsi, separates from the middle in the upper dorsal 
region. The outer and middle portions subdivide. 

Middle Portion. Outer Portion. 

Longissimus dorsi (Longissimus Sacro-lumbalis (Ilio-costalis lum- 

dorsi, p. n.). borum, p. n.). 

Transversalis cervicis (Longissi- Accessorius (Ilio-costalis dorsi, p. 

mus cervicis, p. n.). n.). 

Trachelo-mastoid (Longissimus Cervicalis ascendens (Ilio-costalis 

capitis,^, n.). cervicis, p. n.). 

31. ilio-costalis lumborum (sacro-lumbalis), from outer and superficial 
portion of common mass into angles of lower six or seven ribs. 

31. ilio-costalis dorsi (accessorius), from ribs into which the preceding 
is inserted, but internal to it, into angles of the upper six ribs and trans. 
proc. of the seventh cerv. vert. 

* A commission of anatomical nomenclature has suggested for universal use 
names here marked^, n. (proposed name). It is practically the nomenclature 
of Henle. 



MUSCLES AND FASCIAE OF THE BACK. 143 

M. ffio-costalis a rricis (cervicalis ascendens) continues the series /Vo^ 

angles of upper four or five ribs into posterior tubercles of fourth, fifth, 
and sixth cerv. trans, proc. 

31. longissimus dorsi rises from common mass, has two sets of inser- 
tions — an inner row of round tendons into all the dorsal trans, proc. and 
lumbar accessory proc. ; an outer row to the lowest nine or ten ribs be- 
tween angles and tuberosities, and to whole length of lumbar trans, proc. 
and into lumbar fascia. 

M. longissimus cervicis (transversalis cerv.), from highest four or five 
dorsal trans, proc. into posterior tubercles of trans, proc. of five cerv. 
vert., second to sixth inclusive. 

31. longissimus capitis (trachelo-mastoid), by four tendons from the 
upper dorsal trans, proc. , and from articular proc. of the lower three or 
four cervical vert., into the posterior margin of the mastoid process 
under the splenius cap. and sterno-mastoid. It shows a tendinous inter- 
section near its insertion : it is the only muscle between the splenius and 
com plexus. 

2. Musculi spinalis, spinous muscles, have an arched direction. (1) 
31. spinalis dorsi, close inside the longissimus dorsi and connected with 
it ; origin, lowest two or three dorsal spines and from tendons passing 
from upper lumbar spines to long, dorsi ; inserted by four to nine slips 
into the upper dorsal spines. 

(2) 31. spinalis cervicis, inconstant or different on the two sides from 
lig. nuchse and seventh cerv. spine, and one or two above or below this ; 
inserted into spine of axis or also into third and fourth cervical spines. 

M. sacro-coccygeus posticus, or extensor coccygis (rare), from lower end of 
sacrum to coccyx, represents a strong extensor of lower animals. 

3. 31. transverso-spin all's, a common name for a group all inclined in- 
ward from transverse to spinous processes. 

{a) Mm. Semispinals (half-spinous). — (1) 31. semispinalis dorsi, by 
five or six tendons from the trans, proc. of the dorsal vert., from the 
sixth to the tenth, inclusive ; inserted by just as many tendons into the 
spines of the upper four dorsal and lower two cervical vert, (2) 31. semi- 
spinalis cervicis, covered by the com plexus, rises nearly from the inser- 
tion vertebrae of preceding — viz. upper five or six dorsal trans, proc. ; 
inserted into cervical spines from second to fifth, inclusive, being thickest 
into the axis. (3) 31. semispinalis capitis (complexus) rises by two sets 
of heads : the inner, or biventer cervicis, rises from three or four dorsal 
trans, proc. between the second and sixth ; its superficial fibres are in- 
serted into the external occipital protuberance beside the lig. nuchse ; its 
deeper fibres join the external head. The outer head rises from upper 
dorsal and lower three or four cervical vert, , on the dorsal and seventh 
cerv. from trans, proc, on the remaining cerv. vert, (fourth, fifth, or 
sixth) by two slips from each, one from the posterior tubercle of the 
trans, proc, and one from the lower articular process. These fibres 
unite, join part of the inner head, and are inserted into the inner im- 



144 MUSCLES OF THE TRUNK. 

pression between the two curved occipital lines. A tendinous inscrip- 
tion crosses the muscle near the spine of the axis ; another crosses the 
biventer lower down. 

(b) M. multifidus (spinas) occupies the groove beside the spinous pro- 
cesses from the sacrum to the axis ; rises from deep surface of erector 
spinse, from back of sacrum as low as fourth foramen, posterior extrem- 
ity of ilium, and posterior sacro-iliac ligament; in lumbar region from 
mammillary processes ; in dorsal, from trans, proc. ; in cervical, from ar- 
ticular processes of the four lower vert. The bundles pass up and in, to 
be inserted into the whole length of the spines from the last lumbar to 
the axis : some fibres go to the fourth vertebra above, others to those 
nearer. 

(c) Mm. Rotatores. — (1 ) Mm. rotatores longi, really a part of the mul- 
tifidus, only in dorsal region, from upper edge of a trans, proc. to lateral 
edge of root of the second or third spinous process above. 

(2) Mm. rotatores breves (rotatores dorsi of Quain), eleven in number, 
dorsal region, nearly horizontal, from upper edge of a trans, proc. to 
lower edge of the lamina above. 

Short Muscles. — All those connecting adjacent vertebrae. 

1. Of Flexion-vertebra?. — 1. Mm. interspinales, vertical sets of fibres 
in pairs between contiguous spinous processes; in the neck they are 
round, in the back are usually absent, in the loins are flat from side to 
side. 

2. Mm. Intertransversales (posterior, as there is also an anterior set in 
the neck). — In the lumbar region there are two parts — an inner, inter- 
transversalis post, medialis, from a mammillary process to an accessory 
or mammillary process next above; an external, intertr.post. lateralis, 
between two contiguous trans, proc. In the back the inner portion is 
supplied by the intertransverse ligaments, the outer portion by the lev. 
costarum ; in the neck and upper dorsal region they are single bands be- 
tween the trans, proc. and behind the cervical nerves. 

3. Mm. levatores costarum, twelve on either side, rise from the tips 
of the trans, proc. of the seventh cervical and upper eleven dorsal vert. ; 
continued externally into the external intercostals, and inserted into the 
outer surf ice of the rib belonging to the vertebra below that from which 
it springs, between the tuberosity and angle. Those muscles passing to 
the adjacent rib are lev. cost, breves : in the lower dorsal region are lev. 
cost, longi, which pass over one rib. 

II. Short Muscles of Rotation-vertebra' and Occiput — Five on each 
side ; two rise from the axis and three from the atlas. 1. M. rectus cap- 
itis posticus major. — Origin, spine of axis ; upper border; insertion, into 
and below the middle third of the inferior curved line of the occiput. 
2. 31. obliquus cap. inferior, strongest of these muscles. — Origin, 
upper and posterior part of arch of axis (Henle) ; insertion, back part 
of trans, proc. of atlas. 3. M. rectus cap. post, minor. — Origin, poste- 
rior tubercle of atlas; insertion, into and beneath inner third of inferior 
curved line of occiput, covered partly by the major muscle. 4. M. 



MUSCLES AND FASCTiE OF THE ABDOMEN. 145 

obliquus cup. superior. — Origin^ upper surface of trans, proc. of atlas; 
insertion, impression between outer parts of the occipital curved lines. 
."). M. rectus cap. lateralis. — Origin^ anterior surface of apex of trans. 
proc. of atlas; passes nearly straight up to the jugular process of 
occiput 

The two oblique muscles, with the rect. cap. post, inaj., form the suboccipital 
triangle. 

Suboccipital muscles maybe doubled. M. atlanto-mctstoid., from transverse 
process of atlas to hinder part of mastoid. 

Nerves. — All the above back muscles by posterior primary branches of 
spinal n. 

Actions. — The longitudinal muscles extend the back with a force of 200-400 
pounds : some of the lower muscles may depress the ribs and aid in forced 
expiration ; some of the upper, if fixed above, may act in forced inspiration. 
The muscles of one side produce lateral flexion of the spinal column. The 
eomplexus and transverso-spinalis rotate the head and spine to the opposite side. 
The rectus minor and superior oblique chiefly extend the head ; the rectus major 
and inferior oblique rotate the atlas and skull on the axis ; the major also ex- 
tends the head. The lev. costarum have but little action on the ribs; are re- 
garded as muscles of forced inspiration. The rectus lat. bends the head to one 
side. 



MUSCLES AND FASCIiE OF THE ABDOMEN. 

Describe the abdominal muscles and fascise. 

The superficial fascia of the abdomen has two layers: (1) subcuta- 
neous, containing fat ; (2) deeper contains yellow elastic tissue, correspond- 
ing to tunica abdominalis of animals for support of viscera. From the 
deeper layer is derived the suspensory ligament of the penis ; its lower 
part, fascia of Scarpa, passes over Poupart's ligament and ends just be- 
low in the fascia lata.^ Both layers pass over the spermatic cord to the 
scrotum, become reddish and muscular, forming the dartos. There is 
no deep fascia. 

The abdominal muscles fill the space between the chest, lumbar ver- 
tebras, and pelvis. 

(a) Vertical Muscles. — 1. M. rectus abdominis, separated from its fel- 
low by the linea alba. — Origin, cartilages of fifth, sixth, and seventh 
ribs, and usually bone of fifth, by three slips, sometimes from the ensi- 
form ; insertion, by two tendons, the inner smaller one into the front of 
the symphysis pubis, crossing its fellow of the opposite side, passing down 
and out to adductor fascia, down and in to fascia of penis ; the outer head 
into the pubic crest or space in front of it if the pyramidalis is lacking. 
(Henle considers the insertion as below, as it passes into so much mov- 
able fascia. ) The fibres are interrupted by zigzag tendinous inscriptions, 
the three most constant being one at. the umbilicus, one at the lower end 
of the ensiform, and one between these two: if one or two more are 
added, they are incomplete and below the umbilicus. They do not pen- 
etrate the whole thickness of the muscle ; may extend into the internal 
10— A. 



146 MUSCLES OF THE TRUNK. 

oblique ; are not vestiges of ribs, but of the septa between the original 
vertebral myotomes. 

M. rectus lateralis abd., 1 inch (2.5 cm.) broad, between the external and 
internal oblique muscles, from the tenth rib down over the eleventh to the 
middle of the iliac crest. 

2. M. pyramidalis rests on lower part of rectus inside its sheath, 
separated from it by a special fascia. Origin, front of pubis below in- 
sertion of outer tendon of rectus, passes over the lower third of the 
space between the umbilicus and pubis ; inst rtt <I into the linea alba. Its 
inner fibres are vertical, outer ones oblique. 

The height of the muscle is variable, unlike on both sides, one lacking ; 
both lacking in every fourth case ; doubled on one or both sides. When lack- 
ing the lower part of the rectus is increased in size. 

The linea alba is a fibrous structure from the ensiform to the pubis, 
formed by the union of the oblique and transverse aponeuroses, broadest 
above, \ inch (4-7 mm.), and a little below its middle is the cicatrix of 
the umbilicus. At the lower end it passes in front of the recti, and here 
is detached posteriorly a band of longitudinal fibres = adiminiculum 
lineoe albce, spreading out triangularly behind the outer heads of the 
recti. The linea semilunaris is a narrow part of the internal oblique 
aponeurosis just before it divides into two layers. Linece transversa^ 
correspond to the intersections of the rectus. 

(b) Transverse Muscles. — 1. M. obliguus extemus, or descending oblique, 
muscular on the side, aponeurotic in front. — Origin, outer surfaces and 
lower borders of the lower eight ribs (seven, Henle) by slips in a serrated 
series, five interdigitating with the serratus magnus, the lower three with 
the lat. dorsi, from lumbo-dorsal aponeurosis connected with first lumb. 
vert. The slip from the eighth rib is broadest, the others diminish 
above and below that ; upper and lower digitations rise from near the 
costal cartilages, the intermediate ones at some distance from them. 

The fibres from the last two ribs pass nearly vertically down to the 
anterior half of the outer lip of the iliac crest ; all the rest incline down 
and forward to the aponeurosis. This is wider below than above, meets 
its fellow in the linea alba, is connected with, the costo-xiphoid ligament, 
gives origin to the lowest fibres of the pect. major, or is covered by a 
fascia derived from it ; below it extends from the anterior superior spine 
of the ilium to the spine of the pubis as a thickened border called 
Pm i part's ligament. 

The aponeurosis is perforated by a large opening near the pubis for 
the spermatic cord in the male and round ligament in the female : this 
is the external abdominal ring (annulus inguinalis cutaneus, p. ??.). It 
is oval or elliptical, 1 inch long, ? inch wide in the male, with its base at 
the pubic crest; its sides are the pillars (crus superins and cms informs, 
p. n.) ; the upper or inner is flat and straight, attached to the anterior 
surface of the pubis, decussating with its fellow or passing to adductor 



MUSCLES AND FASCIA OF THE ABDOMEN. 147 

fascia and dorsum of penis ; the lower or external is thin above, and 
below is formed by the inner end of Poupart's lig., attached to the spine 
of the pubis. 

The deepest fibres of Poupart's lig. are sent back to the inner part of 
the ilio-peetineal line for -$ inch, forming a layer called Gimbernat s liga- 
ment, presenting upper and lower surfaces and a concave margin toward 
the femora] ring and vein. Some of the fibres of Gimbernat's lig. or of 
the outer pillar are reflected up and in, under the spermatic cord, behind 
the inner pillar, in front of the conjoined tendon, covering the posterior 
wall of the external ring, and pass to the sheath of the rectus and linea 
alba or interlace with its opposite : this is the reflected Gimbernat's liga- 
ment or triangular ligament of Colles. 

Transverse fibres bind together the oblique fibres of the aponeurosis, 
and where they cross the ring they are called intercolumnar fibres. From 
them a thin membrane is prolonged upon the spermatic cord, known as 
the intercolumnar or spermatic fascia. 

Generally the ext. oblique and lat, dorsi leave a triangular space be- 
tween them on the iliac crest, forming Petit 's triangle, where thirty or 
forty cases of lumbar hernia have been recorded. 

The external inguinal ligament of Henle (lig. inguinale ext.) is a 
strengthening band of fascia along the outer part of Poupart's lig. It 
springs from the anterior superior spine by two flat roots which form a 
short canal for the external cutaneous nerve : it runs transversely, and is 
fused with the iliac fascia at the lower edge of the ext, obi. aponeurosis 
as far as the crural arch ; there it passes over the femoral vessels and is 
lost. It receives fibres from the ext, obi. aponeurosis, and sends fibres 
down to the fascia lata over the sartorius, so that a sagittal section of the 
ligament and connected fasciae is in the form of a St. Andrew's cross. 
The superficial fascia, and with it the skin, are attached to the lig. ing. 
ext., and form the inguinal sulcus (fold of groin). Internally this liga- 
ment gives off the intercolumnar fibres, and may end in them or in the 
ext. obi. apon. or in the lig. ing. int. 

2. M. Obliqiius In tenuis. — Origin, outer half of Poupart's lig., ante- 
rior two-thirds of middle ridge of iliac crest, from lumbar fascia ; inser- 
tion, lower margins of cartilages of last three ribs, its aponeurosis, and 
by conjoined tendon (with transversalis) arching over the inguinal canal 
to the front of the pubis and inner part of ilio-pect. line behind Gim- 
bemat's lig. The aponeurosis splits at the outer border of the rectus ; 
the anterior layer unites with the ext, obi. apon., the posterior with the 
transversalis apon.. which reunite and form the sheath of the rectus; 
the posterior layer is attached above to the ensiform, seventh and eighth 
rib-cartilages. This division of aponeurosis stp-ps a little above halfway 
between the umbilicus and pubis, and below this point the int. obi. apon. 
and transversalis apon. pass wholly in front of the rectus. This de- 
ficiency in the posterior wall of the sheath is marked by a lunated edge, 
concave downward, the semilunar fold of Douglas (linea Douglasii, 
p. n.)\ here the rectus is separated from the abdominal contents by 



148 MUSCLES OF THE TRUNK. 

peritoneum, subperitoneal tissue, transversalis fascia, and a thin con- 
nective tissue which continues the trans, apon. (Note a difference 
between trans, fascia and apon.) 

Int. obi. muscle may present a fibrous inscription or cartilaginous slip op- 
posite the tenth or eleventh rib ; fold of Douglas is often indistinct, may be 
lacking. 

The cremaster muscle, peculiar to the male, is attached externally to 
the inner portion of Poupart's lig., and is continuous with the int. obi. 
fibres : its internal attachment (inconstant) is the spine and crest of the 
pubis ; it descends in folds in front of the spermatic cord to the level of 
the testis, and spreads out in a cremasteric fascia. Some regard this 
muscle as a part of a foetal structure called gubernaculum testis. There 
are some remains of it in the female. 

3. M. Transversalis Abdominis. — Origin, inner surface of the lower 
six rib-cartilages, interdigitating with the diaphragm, from lumbar trans, 
proc. by a posterior aponeurosis, from anterior three-fourths of inner mar- 
gin of iliac crest, outer third of Poupart's lig. This muscle nearly sur- 
rounds the abdomen, and is inserted into the anterior aponeurosis and 
conjoined tendon. This apon. commences for the most part about 1 inch 
from the outer border of the rectus in the linea Spigelii {p. ??.), but 
muscular fibres nearly meet behind the rectus above : the lower third of 
this apon. passes in front of the rectus. 

The posterior aponeurosis is the middle layer of the lumbar fascia or 
lumbo-costal lig. (Henle), between the erector spinae and quad. lumb. 
muscles. The highest part of this muscle is continuous with the triang. 
sterni. 

Muscle may be absent; m. pubo transversalis behind conjoined tendon from 
ilio-pectineal line to trans, fascia or aponeurosis. 

Nerves. — Supplied in general by lower intercostal n. ; int. obi. and trans- 
versalis also by ilio-hypogastric and ilio-inguinal n. ; cremaster by genital 
branch of genito-crural n. 

Actions. — Upon thorax, viscera, or vertebral column ; pelvis and thorax fixed, 
they aid vomiting, expulsion of foetus, fseces, and urine ; vertebral col. fixed, they 
raise diaphragm by pressing up viscera, and so aid expiration; flex thorax to 
front or laterally, or rotate it if vert. col. be not fixed; thorax fixed, draw up 
pelvis in climbing. Pyramidales make linea alba tense. 

LINING FASCIJE OF THE ABDOMEN. 

The transversalis fascia covers the inner surface of that muscle, and 
is continued upon the under surface of the diaphragm : along the inner 
margin of the iliac crest it is attached to periosteum ; for about 2 inches 
internal to the ant. sup. iliac spine it is attached to the back of Poupart's 
lig. and iliac fascia ; next internally it passes down over the femoral ves- 
sels as the anterior portion of their sheath : as it passes under Poupart's 
lig. it is strengthened by the deep crural arch (arcus cruralis), a band of 
fibres inserted into the pubic spine and ilio-pectineal line behind the con- 



LINING FASCIiE OF THE ABDOMEN. 149 

joined tendon : it includes beneath it, between the femoral vein and 
Gimbernat's lig., the femoral ring, through which a femoral hernia may 
descend. 

Halfway between the ant. sup. iliac spine and symphysis pubis is the 
mU rnal abdominal ring (annulus inguinalis abdominalis, p. n. ) : its lower 
edge is vertically $ inch (8 mm.) above Poupart's lig. and 1J inches (4 
to ."> tin. ) from the outer ring. 

From the inner end of the ilio-pectineal line fibres of transversalis 
fascia go in two directions — outward, beneath the internal ring and 
parallel with Poupart's lig., the lig. inguinale int. laferale; upward, on 
the inner side of the ring as the lig. ing. int. mediale (outer and inner 
parts of internal inguinal ligament). These two form a blunt angle, 
limiting the internal ring below and internally. From the margin of 
the ring is prolonged the delicate infundibidiform fascia (processus 
vaginalis fasciae trans.) The ring is the entrance into this process, the 
lower sharp border of which is the plica semilunaris fascice trans, (fre- 
quently lacking). 

In the region of the umbilicus are strengthening fibres covering the 
obliterated umbilical vein — fascia transverscdis wnbilicalis. 

The iliac fascia covers the ilio-psoas muscle, stretched from the iliac 
crest to the iliac portion of the ilio-pect. line : it is continued up on the 
psoas, attached to the sacrum, invertebral disks, internal arched ligament 
of diaphragm, and externally to ilio-lumbar ligament (ant. layer of lumbar 
fascia). Below it passes beneath the femoral vessels, forming the hinder 
part of the femoral sheath : outside the vessels it unites with the trans- 
versalis fascia on Poupart's ligament and with the ext. ing. lig., which 
prolongs it to the fascia lata (iliac portion) ; internally it joins the pubic 
portion of the fascia lata. A strong band is attached to the ilio-pect. 
eminence between the psoas and pectineus, called the ilio-pect. lig. 

Describe the fasciae of the perineum and pelvis. 

FotScioz of Perineum, Superficial. — In the anterior half of the peri- 
neum, continuous with the dartos, is the superficial perineal fascia, or 
fascia of Codes, bound to the ischio-pubic rami as far back as the ischial 
tuberosities : on a line from this tuberosity to the central point of the 
perineum it turns round the transversus perinei muscle and becomes 
deep perineal fascia. There is an incomplete median septum, so that 
extravasated urine distends one side of the scrotum beneath the dartos, 
then penetrates to the other side, then to the front of the abdomen be- 
neath the superficial fascia, but does not pass to the posterior half of the 
perineum nor down upon the thighs. Buck's fascia is the continuation 
forward of Colles' fascia, investing the penis as far as the glans, contin- 
uous with the dartos, and directing the urine as already stated. 

The deep perineal or subpubic fascia or triangidar ligament of the 
urethra is stretched across the subpubic arch on the deep surface of the 
crura and bulb, and consists of two layers : the inferior layer extends 
back to the central point of the perineum, attached to the ischio-pubic 



150 MUSCLES OF THE TRUNK. 

rami, connected at its base with the other layer, and continuous with the 
recurved margin of the superficial perineal fascia. The transverse lig. 
of the pelvis is connected with this layer, and meeting from below the 
arcuate pubic lig. (subpubic) forms an aperture for the dorsal vein of the 
penis. This layer is perforated by the urethra, arteries of the bulb and 
of the corpora cavernosa. Between the two layers of the triangular 
ligament are the membranous portion of the urethra, the constrictor 
urethras, Cowper's glands, pudic vessels, and dorsal nerves of penis. 

The superior (deep) layer consists of right and left lateral halves, sepa- 
rated in the middle line by the urethra close to the prostate, and con- 
tinuous on each side with the fascia covering the obt. int. muscle. The 
levator ani is between this layer and the recto-vesical fascia. 

Fascia} of the Pelvis. — This consists of two parts, obturator and recto- 
vesical fascia. 

The obturator fascia covers the inner surface of the obturator internus 
muscle ; it is attached to the iliac portion of the ilio-pect. line, to the 
body of the pubis, to the great sacro-sciatic notch and great sacro-sci- 
atic ligament, and upper edge of obturator membrane ; below it joins 
the falciform process of the great sacro-sciatic ligament and bounds the 
ischio-rectal fossa externally. Near its upper margin it gives off the 
anal fascia, which covers the lev. ani externally and bounds the ischio- 
rectal fossa internally. 

The fascia of the pyriformis is continued back from the obturator in 
front of the pyriformis muscle and sacral plexus. 

The recto-vesical fascia is attached in front to the back of the pubis, 
and laterally separates from the obturator fascia along a curved line from 
the upper part of the obturator foramen to the ischial spine : this is the 
posterior part of the white line which extends from the pubis to the 
ischial spine. This fascia, covering the upper surface of the lev. ani 
muscle, passes to the prostate gland, bladder, rectum, and from side to 
side across the median line. The part to the prostate and neck of blad- 
der from the pubis consists largely of involuntary muscular fibres, the 
anterior true ligaments of the bladder, or pubo- prostatic ligaments; out- 
side them are the lateral true ligaments, and the part going to the rec- 
tum is the lig. of the rectum. The anterior part of the fascia meets the 
bladder along its junction with the prostate, and divides into two layers : 
the upper (ascending) unites with the muscular coat of the bladder, and 
is attached just outside the vesicuhe seminales ; the inferior layer (de- 
scending) forms the sheath of the prostate, and at its apex is continued 
into the upper layer of the triangular ligament; it also passes between 
the bladder and rectum and forms the front of the sheath of the latter. 
The vagina receives the recto-vesical fascia in a manner similar to the 
prostate. 

Describe the muscles of the perineum. 

Two groups— anal and genito-urinary, with a superficial and deep set 
in each. 



MUSCLES OF THE PERINEUM. 151 

A. In the Male.— {a) Anal Muscles. — The internal or circular sphinc- 
ter is a thick ring of unstriped muscle continuous with the circular fibres 
of the rectum. 

The external sphincter^ 1 inch in depth, is elliptical, attached by a 
small tendon to die coccyx, encloses the anus, and superficial fibres end 
in skin ; some decussate across the median line ; a few deep ones are 
continuous from side to side, but a large part blend with the muscles 
at the "central point." 

The central point of the perineum is the median part of a tendinous 
septum in which several muscles meet: it is 1 inch in front of the anus, 
behind the bulb of the urethra ; may be absent. 

The levator ani rises from the pubic body, adherent to and between 
the obt. and recto-vesical fasciae, from the "white line," spine of the 
ischium, and upper layer of triangular ligament, The hinder fibres pass 
down and in to the coccyx. The foremost run almost directly back to 
the "central point," the intervening ones to the lower end of the rec- 
tum and median aponeurosis between coccyx and anus, common to the 
two muscles. 

This muscle is divided by a cleft just below the obturator canal into two 
parts : the anterior pubo-coccygeus (Savage) is alone connected with the rec- 
tum ; its outer fibres pass over the side of the prostate, continue the ext. 
sphincter upward, unite with its fellow behind the bowel, and are inserted 
into the coccyx; the inner fibres pass between the two sphincters and join 
the longitudinal fibres of the rectum and decussate in front of the anus. The 
hinder part of the muscle, ischio-coccygeus (Henle), passes from the pelvic 
fascia and ischial spine to the margin of the coccyx and median aponeurosis. 

The cocq/geus, or levator coccygeus, rises by its apex from the ischial 
spine and obturator fascia, and is inserted by its base into the margin of 
the coccyx and lower part of the sacrum. This with the above muscle, 
on both sides, constitute the pelvic diaphragm. 

M. sacro-coccygeus anticus, curvator coecygis, from anterior surface of sacrum 
to anterior surface of coccyx. 

(b) Genito-xirinary Muscles. — Three on each side and a central deep 
one. 

Transversus Perinei. — Origin, ischial tuberosity passes forward and 
inward to unite with its fellow, the external sphincter, and bulbo-cavern- 
osus at the " central point." 

Very variable, inconstant insertion, absent, composed of several slips. M. 
gluteo-perinealis from glut. max. to this muscle. 

Ischio-cavernosus, or Erector Penis. — Origin, inner part of tuberosity 
and ramus of ischium, behind and on each side of the attachment of 
cms penis : its tendon spreads over the crus, and is inserted into the 
outer and under sides of that body at its fore part. 



152 MUSCLES OF THE TRUNK. 

Houston describes the m. compressor reuse dor sails penis, rising in front of the 
cms and erector penis, and joining its fellow above dorsal vein ; it is well de- 
veloped in the dog. 

Jhilbo-cavernosus, or ejaculator urinae, unites with its fellow in a median 
raphe continued forward from the ''central point," the two covering the 
bulb and part of the corpus spongiosum. Its fibres ascend from the 
raphe" and end on the dorsum of the corpus spong. by joining its fellow; 
at the fore part some pass to the outer side of the corpus cavernosuin 
and send an expansion over the dorsal vessels ; some of the posterior 
fibres unite with the under surface of the triangular ligament. 

The fibres surrounding the bulb are somewhat distinct from the rest, and 
have been described as the m. compressor hemispluerum balbi. 

The above three muscles and enclosed triangular space are between 
the superficial and deep perineal fasciae — i. e. below the lower layer of 
the triangular ligament. 

The constrictor or compressor urethrce rises from the ischio-pubic rami, 
from the two layers of the triangular ligament, between which it is 
placed, and surrounds the membranous portion of the urethra, forming 
a kind of sphincter. A median raphe sometimes divides the muscle. Its 
hindermost fibres have been described as the trans, perinei profundus. 

Most of the fibres pass transversely, others obliquely, others circularly 
around the urethra, and on the inferior surface is a longitudinal slip from the 
base to the apex of the triangular ligament. 

Nerves. — External sphincter by fourth sacral and inf. hemorrhoidal of 
pudic ; lev. ani by fourth sacral and perineal branch of pudic ; coccygeus by 
fourth sacral ; the three superficial gen. -urinary muscles by the perineal 
branch of the pudic ; constrictor urethras by dorsal nerve of penis. 

Actions. — Int. sphincter wholly involuntary, external usually involuntary, 
but made firmer by act of will ; lev. ani and coccygeus support and raise floor 
of pelvis, and thus have to do with forced expiration ; the levator also assists 
in emptying the lower rectum, raising and expanding its aperture, but some 
of its fibres act with the ext. sphincter in closing the anus; the transversi fix 
the " central point " and give support to the ejaculator muscles; the ischio- 
cavernosi compress the crus and help produce and maintain the erection of 
the penis; the bulbo-cavernosi forcibly eject fluid mostly voluntarily at the end 
of micturition, involuntarily in the emission of semen ; they also are supposed 
to aid erection of penis ; the constrictor urethrse assists the bulbo-cavernosi in 
clearing the urethra and. erects penis (Henle). 

B. In the female, the transversus perinei, ext. sphincter, lev. ani, erec- 
tor clitoridis (ischio-cavernosus) correspond to similar muscles of the 
male, the sjmincter vac/ince to the bulbo-cavernosi. The constrictor ure- 
thral is the trans, perinei profundus, and differs from that of the male 
by being divided into lateral halves by the vagina. 

Describe the diaphragm or midriff. 

A partition between the abdomen and thorax, rising by muscular fibres 
as vertebral, costal, and sternal portions. 



THE DIAPHRAGM. 153 

The crura, or pillars of the vertebral portion, connected with the ant. 

common lig., rise from the bodies and intervertebral SUDS, el' the lumbar 
vertebrae, the right from the second, third, and fourth, the left from the 

second and third : they arch over the aorta from right to left, and meet 
behind it from left to right. The muscular fibres from them form a 
figure 8, leaving an opening for the oesophagus. The internal arched 
ligament passes over the psoas muscle from the outer side of the first 
lumbar body to the second trans, proe. The external arched ligament 
passes over the quad, lumborum from the second trans, proc. to the 
last rib ; they are the upper margins of fascia covering those muscles ; 
an arched ligament may pass over both muscles ; muscular fibres of 
the diaphragm rise from both. 

The costal portion rises from the lower six cartilages, interdigitating 
with the transversalis abd. The sternal portion is very short — a single 
muscular .slip, sometimes two, from the ensiform cartilage. 

The central tendon, trefoil, forms the highest part, convex in front, 
concave behind ; has three lobes, the right being the largest, the left the 
smallest ; the tendinous fibres are interwoven in every direction. 

There are three foramina : the hiatus aorticus, in front of the first 
lumbar, transmitting the aorta, thoracic duct, and vena azygos mag. ; the 
foramen for the oesophagus, opposite tenth dorsal vert., entirely sur- 
rounded by muscle, oval, transmits oesophagus, pneumogastric nerves, 
and branches of the coronary artery; the foramen quadratum for vena 
cava is in the highest part of the central tendon, at level of disk between 
the eighth and ninth dorsal vert. ; its sides are firmly attached to the 
vein. A sterno-diaphragmatic ligament passes to this foramen. 

Small foramina are in the crura for splanchnics on both sides, for 
small azygos vein on left side : the sympathetic cord perforates the crus 
or passes under the internal arched ligament. 

There are four weak places: (1) between costal and vertebral portions 
near quad. lumb. ; (2) between costal and sternal portions = Larrey , s 
spaces; (3) oesophageal opening; (4) where sympathetic cords^ pierce 
crura. Leftside, as a whole, is the weaker: at Larrey's space is peri- 
toneum below, then areolar tissue, then pericardium on left side and 
pleura on right side. 

Highest point of diaphragm on right side in dead body is level of 
fifth rib-cartilage with sternum ; on left side of sixth cartilage with 
sternum (Quain) ; mid-portion is flat, supports the heart, and is nearly 
immovable. A considerable extent of origin of diaphragm is in contact 
with the thoracic wall. 

Relations are, above, pleurae and pericardium, lungs, and heart; below, 
peritoneum, liver, stomach, pancreas, spleen, and kidneys. 

Nerves. — Phrenics, lower intercostals, and sympathetic. 

Actions. — By its contraction and descent the viscera are pushed down and 
thorax lengthened; it elevates the ribs when its vault is supported by the 
abdominal viscera : its anterior fibres oppose forward movement of the 
sternum. 



154 MUSCLES OF THE TRUNK. 

MUSCLES AND FASCIJE OF THE BREAST. 
Describe the breast muscles and fasciae. 

Fascia of Pectoral Region. — Superficial contains the mammary gland, 
sending septa into it and supporting it. The deep fascia is thin : a part 
of it is the costo-coracoid membrane behind the pect. major ; this en- 
sheathes the subclavius, and its posterior layer blends with the sheath 
of the axillary vessels. The anterior layer from the coracoid to the first 
rib may be called the costo-coracoid ligament: it is prolonged down, in- 
vests the pect. minor, and merges into the axillary fascia at the border 
of the pect, major. The axillary fascia stretches between the two folds 
of the axilla, and is continuous with the sheath of the vessels and apo- 
neurosis of arm. 

a. Superficial Breast-muscles. 

These muscles converge to their insertion into the upper extremity 
and its girdle : the deep ones belong to the bones of the trunk, and are 
in three layers like the transverse ones of the abdominal wall. 

First Layer. — M. pectoralis major, two portions, clavicidar and 
sterno-costal ; the clavicular portion rises from the inner half of the 
anterior surface of the clavicle and sterno-clavicular capsule, the sterno- 
costal from the sternum (superficial part, Henle), and upper six rib- 
cartilages (deep part, Henle) and from anterior sheath of rectus and 
ext. obi. apon. The fibres converge to be inserted by two tendons, united 
along the lower margin, into the external bicipital ridge : the clavicular 
and upper sterno-costal parts form one tendon with straight fibres : the 
lower sterno-costal part twists so that its lowest fibres are inserted highest 
up ; a bursa separates this from the other anterior tendon. This poste- 
rior layer also gives off three expansions— one over the biceps tendon to 
the capsule of the shoulder-joint, one lining the bicipital groove, and one 
to the fascia of the arm. 

Variable in extent of origin and separation of heads. M. chondro-epitro- 
chlearis, from one or two rib-cartilages below pect. roaj., or from it or from 
ext. obi. apon. to fascia of arm, internal intermuscular septum, or inner epi- 
condyle. M. sternalis brutorum lies on pect. maj. parallel to sternum; passes 
from sheath of rectus or third to seventh cartilages to sterno-mastoid, to 
upper cartilages, to sternum or pect. maj. If two are present, they may 
unite across the manubrium. 

Second Layer. — 1. M. subclavius rises from the groove on the under 
surface of the clavicle and recess between the conoid and trapezoid liga- 
ments ; inserted into junction of first rib with its cartilage between fibres 
of costo-clavicular ligament. 

May be attached to coracoid, and not to clavicle, or to both, or to scapula, as 
m. sterno-scapularis ; m. stenw-cJavicuIaris anticus from manubrium: if both are 
present, a digastric interclavicular muscle may connect them across the manu- 
brium. Another variety of this is m. supraclavicula vis, from upper edge of 
manubrium, either anteriorly or posteriorly, behind sterno-mastoid to upper 



MUSCLES AND FASCIAE OF THE BREAST. 155 

surface of clavicle (1 in 20). There may be the acapulo-clavicularU or coraco- 

claviculuris. 

2. M. pectoralis minor from three ribs near their cartilages, usually 
third, fourth, and fifth, often second, third, and fourth or fifth, and from 

intercostal aponeuroses; insertion, inner border and upper surface of 
coracoid ; a bursa is under its insertion (1 in 40 cases). 

Each costal origin may remain separate in the muscle: its insertion may be 
continued into the capsule and great tuberosity; the insertion is represented 
normally by the coraco-humeral ligament. Absence of whole muscle. M. 
pectoralis minimus (rare), from first costal cartilage to coracoid. 

Third Layer. — M. serratus anticus, p. n. (serratus magnus), placed 
between ribs and scapula. Origin, first eight or nine ribs by as many 
slips : the first slip is attached to two ribs ; insertion, posterior border 
of scapula and into the flat surfaces at upper and lower angles, not in 
the subscapular fossa. There are three sets of fibres : (1) first digita- 
tion, from first and second ribs, passes up to flat area at upper angle ; 
(2) second and third digitations, from second and third ribs, pass down 
in a thin triangular layer to the whole line between the upper and lower 
angles; (3) the remaining five or six digitations converge, some up and 
some down, to the flat surface in front of the lower angle. 

Varieties. — Slip from tenth rib ; lower digitations or slip from first rib ab- 
sent ; may be united with levator scapulse, as is the case in many mammals. 
May be a bursa at the upper angle of scapula or between the serratus and 
chest-wall. 

Nerves. — The pectoralis major by the two anterior thoracics ; the minor by 
the int. ant. thoracic n. ; the subclavius by the fifth and sixth cervical ; ser- 
ratus anticus by the posterior thoracic, upper division by fifth c, middle by 
sixth c. (often fifth c. also), lower by sixth and seventh c. 

Actions. — Pect. major. 

Arm at Side. Arm Abducted to 90°. Arm Raised High. 

First part of muscle Draws arm forward Draws arm forward to 

draws arm up and and rotates in. horizontal, and no far- 

in. ther. 

Second part of muscle Draws arm down, in, Adducts, draws down. 

draws arm down and and rotates in. 

rotates in. 

It assists the lat. dorsi in adduction, opposes it in flexion; lowest fibres are 
best adductors ; succeeding ones draw forward ; used in swimming. Fixed 
above the pectorales, draw body forward; the major does not draw up the 
ribs, the minor does not seem to, so that they have no inspiratory action. 

The subclavius depresses clavicle or steadies it ; may act in inspiration ; sup- 
ports sterno-clavicular joint. The pect. minor draws coracoid down and for- 
ward, depresses shoulder, throws lower angle of scapula backward, acts with 
levator and rhomboidei in rotating scapula. The scapula is slung by the ser- 
ratus magnus and rhomboidei, is kept in equilibrium by them ; lower portion 
of serratus, combined with trapezius, rotates scapula on an axis near its supe- 



1 56 MUSCLES OF THE TRUNK. 

rior anjjle and elevates shoulder; upper fibres bring scapula forward and 
down, assisted by pect. minor; whole muscle brings scapula forward, acts in 
all movements of pushing, keeps scapula pressed to ribs; of no importance in 
respiration; middle fibres only might pull ribs down. 

b. Deep Breast-muscles. 

First Layer. — Mm. intercostales externi, thicker behind than in 
front, are directed obliquely downward and forward between the borders 
of two ribs : they extend from the tuberosities to the outer ends of the 
cartilages, not quite reaching them above, but continued along their bor- 
ders, in the lower two spaces. They are continued to the sternum as 
(Ulterior intercostal aponeuroses or ligg. intercostalia ext. 

M. supracostalis from anterior end of first rib, from cervical fascia or scaleni 
to fourth or to second and third ribs. 

Second Layer. — Mm. intercostales interni, thicker in front, incline 
down and back, but less obliquely than the external set; are attached to 
the inner surfaces of two ribs. Anteriorly they reach the sternum, and 
the last two are continuous with the int. obi. muscle ; posteriorly they 
go to the angles or a little beyond. Their deficiency behind is supplied 
by the post, intcrcost. apon,, which merge on one side into the ant. 
cost. -trans, lig., and on the other into a thin fascia between the muscles. 

Third Layer. — Mm. Transversi Thoracis.— 1. M. trans, thoracis 
posterior (subcostal muscles) are small slips on inner aspect of thorax, 
connected with int. intercostals near angles of ribs ; run in same direc- 
tion as int. intercost. , and extend over one or two spaces ; origins, reach 
from twelfth rib to third ; insertions, from tenth to second. 

2. M. Transversus Thoracis Ant. (triangularis sterni). — Muscular and 
tendinous fibres behind the costal cartilages rise from ensiform, lower 
part of sternum, and cart, of lower two or three true ribs ; fibres pass 
up and out ; lowest are horizontal, middle oblique, and upper ones nearly 
vertical ; inserted to inner surfaces and lower borders of sixth to second 
costal cartilages, inclusive. It is a continuation upward of the trans, 
abd. muscle ; may be lacking on one or both sides. 

Nerves. — All by intercostal n. 

Actions. — Costal and diaphragmatic respiration are normally combined ; the 
thorax is increased antero-posteriorly by a forward movement of the sternum, 
transversely by elevation and eversion of ribs, vertically by descent of dia- 
phragm ; extension of the vertebral column is also an agent. There are three 
views as to action of the intercostals: Hamberger's, that the external elevate 
and internal depress the ribs ; Hutchinson's, that the external and anterior 
parts of the internal elevate, and the rest of the internal depress ribs ; Hal- 
ler's is best — that (1) ribs are not joined as by a pivot to vertebral col.; (2) 
are not parallel bars, but convex arches; (3) no two ribs can move as they 
please, being connected above and below, but all move as a system: if fixed 
point be above, both external and internal intercostals elevate the ribs and 
are inspiratory muscles ; fixed below, they both depress and assist expiration. 



MUSCLES AND FASCIA OF THE NECK. 



157 



Inspiration. 



Typical Forces. 
Elasticity of thorax. 
Diaphragm. 
Scaleni. 

Iutercostals. 



Expiration. 



Typical Forces. 
Elasticity of thorax. 
Elasticity of lungs. 
Weight of thorax and shoulder girdle. 
Weight of abdomen. 
Intercostals. 



Accessory Forces. 
Sterno-mastoid. 
Subclavius. 

Muscles of back of neck. 
Serratus post. sup. 
Levatores costaruni. 



Accessory Forces. 
Quadratus lumborum. 
Triangularis stern i. 
Serratus post. inf. 
Abdominal muscles. 
Levator ani and coccygeus. 



MUSCLES AND FASCIA OF THE NECK. 
Describe the neck-muscles. 

Mostly vertical, a superficial or anterior group, some resembling the 
recti abd. , a deep or posterior group corresponding to the intercostals 
and serratus anticus. 

Anterior Nech-muscles. 

Long 3Iuscles. — 1. Platysma myoides (M. subcutaneus colli) is a pale, 
thin muscular sheet over the front and side of the neck and lower part 
of face. Origin, skin and subcutaneous tissue over deltoid, pectoral 
and trapezius muscles in a line from anterior end of second rib to acro- 
mion ; fibres pass up and in over clavicle, and are inserted into the lower 
jaw : the two muscles meet at the hyoid, and the right overlaps the left 
one ; the posterior fibres blend with the depressor anguli and orbicularis 
muscles and fasciae. The muscle does not rise from bone ; inserted into 
bone, muscle, and fascia. 

A slip to this muscle from the mastoid or occiput ; the m. occipitalis minor 
from the fascia over the upper end of the trapezius transversely to the fascia 
over the insertion of the sterno-mastoid (8 out of 25 cases). Platysma repre- 
sents the panniculus carnosus of mammals, a skin muscle. 

Nerves. — Inframaxillary branch of facial, but as this unites with the super- 
ficial cerv. n., it may get some spinal innervation. 

Action. — Draws angle of mouth down and out ; may depress lower jaw ; being 
curved, it tends to redress itself, carries skin of neck forward, and is said to 
be useful in singing by removing pressure from great vessels ; used in swal- 
lowing and expressing sudden terror ; some say propels saliva from parotid. 

Describe the deep cervical fascia (anteriorly). 

It passes from the trapezius muscle beneath the platysma over the 
posterior triangle of the neck, invests the sterno-mastoid, and passes 
over the anterior triangle to the median line. It is attached below to 
the clavicle, and perforated by the ext. jugular vein ; attached above to 



158 MUSCLES OF THE TRUNK. 

the lower jaw, and becomes the parotid fascia and stylo-maxillary Jig. 
In front it is attached to the hyoid bone, and splits below the thyroid 
gland : the anterior layer goes to the anterior surface of the sternum, 
and the posterior, covering the sterno-hyoid and thyroid muscles, is at- 
tached to the interclavicular lig. ; between these two layers is the supra- 
sternal space, extending a short distance on either side behind the sterno- 
mastoid as the supraclavicular recess. Prolonged from the deeper layer, 
a fascia invests the posterior belly of the omo-hyoid and holds it down to 
the first rib, there connected with the costo-coracoid membrane. A pro- 
cess also passes behind the depressors of the hyoid, invests the thyroid 
body, passes to the trachea, forms the carotid sheath, and extends to the 
pericardium. Deepest of all is the prevertebral fascia. Inside the phar- 
yngeal muscles is the pharyngeal aponeurosis, outside them their proper 
fascial layer (buceo-pharyngeal), connected to the prevert. fascia by areo- 
lar tissue, fornfing the retro-pharyngeal space. A prolongation* of the 
prevertebral fascia forms the axillary sheath. 

Regions of Neck. — Suprahyoid, submaxillary, submental, infrahyoid, 
fossa suprasternalis ; on either side the larynx are sulci carotidei, sterno- 
mastoid region, fossa supraclaviculars minor, above sternal end of clav- 
icle, fossa supracl. major, between trapezius and sterno-mastoid. 

2. M. Sterno-cleido-mastoideus (its full name should mention its inser- 
tion into the occipital bone). — Origin, sternal head, thick and round, 
from anterior surface of manubrium ; clavicular, from inner third upper 
surface of clavicle. The two portions meet, pass up and back to the 
anterior border and outer surface of mastoid and outer half or more of 
the superior curved line of the occiput, to meet the trapezius. Spinal 
access, nerve pierces the under surface of the external portion. 

Sterno-mastoid and cleido-mastoid parts may remain separate; the latter 
will be pierced by the sp. access, nerve. A third factor may be added, cleido- 
occipital, origin and insertion outside the cleido-mastoid. In animals without 
a clavicle the cleido-mastoid part is continued into the great pectoral or 
deltoid. 

M. supraclavicularis proprius is attached to the clavicle at each end, forming 
an arch above the middle of the bone. 

M. levator claviculsB, a misplaced part of the sterno-mastoid or scalenus, 
springs from tbe middle of the clavicle, and is inserted into the fifth and fourth, 
fourth and third, or third and second cervical trans, proc. 

Connected with the insertion of the sterno-mastoid is the M. Trans- 
versus Kucha' ( ] 8 out of 25 cases). It is covered by the insertion of the 
trapezius, lies below the superior curved line, concave above, rises from 
the inner part of this line and ext. occip. protuberance, and is inserted 
into this line externally and into the sterno-mastoid aponeurosis. When 
absent it is represented by tendinous fibres. Its purpose seems to be to 
prolong the sterno-mastoid insertion backward. 

Nerves. — Both by spinal accessory, offsets of which are joined by the second 
cervical. 



MUSCLES AND FASCIJE OF THE NECK. 159 

Actions. — The two sterno-mastoids draw the head and neck forward toward 
the sternum ; one, acting slightly, ilexes the head (extends, Benle) and flexes 
laterally and rotates, so that the lace looks up and toward the opposite side. 
Fixed above, the muscles elevate thorax in forced inspiration. 

3. Digastric muscle (111. biventer mandibular) has two bellies united 
by a rounded tendon : the posterior belly rises from the digastric fossa 
oi the temporal bone, passes down, in, and forward toward the hyoid 
bone. The anterior belly is attached close to the symphysis of the lower 
jaw and directed down, back, and slightly outward : the intervening 
tendon is attached to the body and great cornu of the hyoid by an 
aponeurosis and by the stylo-hyoid muscle, which is pierced by the 
digastric tendon. The anterior bellies of the two muscles are connected 
by a dense aponeurosis. 

Varieties. — Slip from styloid process to post, belly; slip from near angle of 
lower jaw to ant. belly ; ant. belly may be split and some fibres cross the 
median line; muscle maybe rnonogastric from mastoid to middle of lower 
jaw ; digastric tendon may be in front of or behind the stylo-hyoid. The 
mento-hyoid is a median slip (or two parallel bauds) from the hyoid to the 
chin. 

Nerves. — Ant. belly by mylohyoid branch of inferior dental from third 
division of fifth nerve ; post, belly by facial. 

Actions. — Either an elevator of the hyoid or depressor of lower jaw, accord- 
ing to whicb is fixed ; its insertion is not close enough to the hyoid to allow 
independent action of either belly. 

Hy oid-bone Muscles. 

1. Between Base of Skull and Hyoid.— M. Stylo-hyoidens. — 
Origin, by narrow tendon from back of styloid process near its root ; 
insertion, usually divided for transmission of digastric tendon, and the 
two portions pass ununited to the hyoid at the junction of the great 
cornu and body ; almost always a slip ends in the digastric tendon. 

May be wanting, may be double; inserted into digastric tendon ; fibres con- 
tinued to omo-, thyro-, or mylo-hyoid muscles. M. stylo-hyoideus alter, (stylo- 
chondro-byoideusorstylo-hy. prof.), from styloid process to small cornu, accom- 
panying or replacing the stylo-hyoid lig. 

II. Between Thorax and Hyoid.— First Layer.— 1. M. Stemo- 
hyoideus. — Origin, back of sternum and sterno-clavicular joint, or from 
joint and clavicle, from clavicle only, sometimes from first costal carti- 
lage ; insertion, inner half of lower border of hyoid body. Its inner 
border approaches its fellow; are far apart below. 

Transverse intersection at level of omo-hyoid tendon, analogous to rect. 
abd. ; muscle may be doubled or absent. M. cleido-hyoideus from clavicle to 
hyoid in front of sterno-hyoid. 

2. M. omo-Jiyoideus, ribbon-shaped, has two bellies and an intermediate 
tendon. Origin, upper border scapula near notch or from transverse 
ligament ; passes forward under trapezius across scaleni, beneath sterno- 



160 MUSCLES OF THE TRUNK. 

mastoid, then vertically to lower border of hyoid, partly beneath and 
partly in front of the sterno-hyoid insertion. Its tendon beneath the 
Bterno-mastoid at level of cricoid cartilage is enclosed in the deep cer- 
vical fascia, which is prolonged down to the sternum and first costal 
cartilage, while the fascia investing its posterior belly descends to the 
clavicle. 

Varieties. — Frequent, doubled or absent ; clavicle may be sole origin of post, 
belly (m. cleido-hyoideus) ; band of fascia may take tbe place of its ant. belly ; 
the post, belly may have an accessory slip to the clavicle, first rib, or cervical 
fascia (m. coraco-cervicalis), others to the sterno-mastoid, sixth cerv. trans, 
proc. or fascia of scalenus, M. cervico-costo-li amend is has been seen, from 
small tuberosity of humerus, inserted by two tendons, one to sixth cerv. 
trans, proc, one to anterior end of first rib. The omo-hyoid and sterno-hyoid 
muscles are parts of the same muscular sheet; the fascia binding down the 
post, belly may contain striped muscular fibres ; the varieties of the muscle 
come from the different degrees of cleavage of this sheet. 

Second Layer. — 1. M. sternothyreoideus lies behind the sterno- 
hyoid, and rises from posterior surface of manubrium internal to the 
sterno-hyoid, variably from first and second costal cartilages, diverges 
from its fellow ; inserted into oblique line of thyroid cartilage, covering 
some fibres of the inf. constrictor. 

Muscles united at origin, absent or doubled ; transverse inscriptions ; a slip 
to fascia of neck (costo-fascialis), or one from the carotid sheath to the outer 
border of the muscle. 

2. M. thyreohyoideus, a continuation of the preceding from the oblique 
line of the thyroid cartilage to the outer half of the lower border of the 
hyoid and anterior half of great cornu. 

M. hyo-fhyroideus lat. from apex of great cornu to apex upper horn of thy- 
roid cart. M. cricoliyoideus between cricoid cart, and hyoid bone. 

M. transversus colli, in the lower part of the neck, represents the mm. trans, 
abd. and thoracis: it springs from the upper edge of the first costal cartilage, 
and passes, fan-shaped, in many fine tendinous fibres between the sterno- 
hyoid and sterno-thyroid muscles, meeting or crossing its fellow in the middle 
line: some fibres end in the interclavicular ligament or stern o-clavicular 
capsule. 

III. Muscles between Lower Jaw and Hyoid Bone. 

First Layer. — M. Mylohyoideus. — Origin, from mylp-hyoid ridge of 
lower jaw, extending from last molar tooth nearly to symphysis ; fibres 
pass inward, back, and downward, hinder ones to body of hyoid, a larger 
number into the median raphe between the two muscles, which extends 
from near the symphysis to the hyoid ; the posterior border is free ; the 
two muscles form the "diaphragm of the mouth." 

May be closely connected with or replaced by ant. belly of digastric; may 
receive slip from other hyoid muscles; may be deficient at fore part. 

Second Layer. — J/, geniohyoideus has a narrow origin from the 



MUSCLES AND FASCLffi OF THE NECK. 161 

inf. mental spine; fibres pass straight back to anterior surface of body 
of hyoid, and frequently send a small slip to the small cornu over the 
hyoglossus or another to the great cornu. It may be blended with its 
fellow or doubled. 

Nerves. — Stylo-hyoid by facial, mylo-hyoid by mylo-hyoid branch of inf. 
dental of third div. of fifth; all the others of this group attached to the 
hyoid bone apparently by the hypoglossal, but really by the first, second, aud 
third eery, nerves vid the communicans and descendens noni (so called). 

Actions. — Stcrno-hyoid and omo-hyoid depress the hyoid bone; the sterno-thy- 
roid depresses that cartilage, may make vocal cords tense, but with the thyro- 
hyoid depresses the hyoid bone ; the latter also draws up the larynx ; may 
relax vocal cords, and produces descent of epiglottis. These muscles restore 
the larynx and hyoid after the act of swallowing, and depress them in utter- 
ance of low tones. The infrahyoid muscles may act in forced inspiration. 

The mylo-hyoid and genio-hyoid elevate the hyoid and draw it forward, or 
depress the lower jaw, depending upon which is fixed : the former raises the 
floor of the mouth and forces food back. The stylo-hyoid acts only on the 
hyoid bone ; aided by the mid. constrictor, it draws it up and back. 

Describe the extrinsic muscles of the tongue. 

31. genio-hyoglossus, fan-shaped, is placed vertically in contact with 
its fellow. Origin, superior mental tubercle; lower fibres pass to body 
of hyoid and side of pharynx, superior to tip of tongue, and intermediate 
to whole length of tongue, some decussating across the median line. 

Slips may pass to the epiglottis, stylo-hyoid lig., or small cornu of hyoid 
bone. 

31. Jn/oglossus is flat and quadrate. Origin, whole length of great 
cornu and lateral part of hyoid body; insertion, posterior half of tongue, 
where fibres spread forward and inward over the dorsum, joining the 
styloglossus. The fibres from the hyoid body may be called the hasio- 
glossus, those from the great cornu the keratoglossus. 

The iriticeo-glossus rises from the cartilago triticea in the thyro-hyoid lig., 
and enters the tongue with the posterior part of the hyoglossus. 

The chondroglossus is often described as a part of the above, but is 
separated from it by the phaiyngeal fibres of the genio-hyoglossus. Ori- 
gin, inner side of base of small cornu and from part of hyoid body ; its 
fibres end on the dorsum of the tongue near the middle line. 

31. Styloglossus. — Origin, front of styloid process near apex, and 
largely from stylo-maxillary lig. ; insertion, side and under part of tongue 
as far as tip, decussating and blending with the hyoglossus and palato- 
glossus. 

The lingualis is the intrinsic tongue-muscle, presenting inferior, supe- 
rior, transverse, and vertical fibres, with a median fibrous septum. 

M. myloglossus is an accessory slip of the styloglossus from angle of jaw 
or stylo-max. lig. to the tongue. 31. stylo-atiricidaris, from cartilage of exter- 
nal auditory meatus to styloid process or styloglossus muscle : a fibrous band 
is often found here. 

11— A. 



162 MUSCLES OF THE TRUNK. 

Nerves. — Motor supply by hypoglossal. 

Actions — Genio-hyoglossus, hinder part protrudes the tongue, front part re- 
tracts, middle part or nearly whole muscle depresses and makes dorsum con- 
cave ; in hemiplegia the sound fibres push apex over to paralyzed side. The 
hyoglossus and chondroglossus retract, depress, and make dorsum convex; the 
styloglossus draws tongue back, elevates the base, and makes dorsum concave. 

Describe the muscles of the pharynx. 

There are two layers : an outer, called constrictors, three in number, 
with a transverse direction ; an inner, called elevators, two in number, 
with a longitudinal direction. 

Inferior Constrictor (laiyngo-pharyngeus). — Origin, cricoid cart, at 
lower and back part, inf. cornu, oblique line and upper tubercle of the 
thyroid cart, ; some fibres continue into it from sterno-thyroid and crico- 
thyroid muscles. It unites with its fellow in the median line ; its inferior 
fibres are horizontal, and a few enter the longitudinal layer of the 
oesophagus, and highest end on a raphe about 1 inch below the basilar 
process. Superficial fibres of one side become deep in the other, or may 
join the fibres of another constrictor. This covers the middle con- 
strictor ; the sup. laryngeal nerve and vessels enter the larynx above its 
upper border, and the inferior nerve and vessels beneath its lower border. 

Middle Constrictor (hyo-pharyngeus). — Origin, large and small cornua 
of hyoid, from stylo-hyoid lig. ; fibres diverge greatly, covering nearly 
the whole length of the pharynx, and meet behind in the median line : 
the lowest are beneath the inf. constrictor, the highest overlap the sup. 
constrictor, the intermediate ones are transverse. The stylo-pharyngeus 
muscle separates this from the sup. constrictor. 

Fibres may come from the hyoid body, tongue, or mylo-hyoid ridge; a fre- 
quent slip from the lateral thyro-hyoid lig. is the m. syndesmo-pharyngcus. 

Superior Constrictor (cephalo-pharyngeus). — Origin, side of tongue, 
mucous membrane of mouth, alveolus at end of mylo-hyoid ridge, pterygo- 
max. lig., hanmlar process, and lower third of internal pterygoid plate: 
the fibres curve back and blend with the opposite muscle or end in the 
aponeurosis which fixes the pharynx to the basilar process. Of all the 
constrictors, only the upper half of this muscle ends in a raphe (linea 
alba). The upper margin curves round the lev. palati and Eustachian 
tube ; the space intervening, closed by fibrous membrane, is the sinus of 
Morgagni. 

These muscles are covered externally by dense connective tissue, which 
is prolonged forward to the pteiygo-max. lig., and is continuous with the 
membrane over the buccinator muscle ; hence it is called the bucco- 
pharyngeal fascia. Next comes the muscular layers, next the pharyn- 
geal apon., and next the mucous membrane. 

The m. stylo-pharyngeus rises from the inner surface of the styloid 
process near the root, passes down and in under cover of the middle 
constrictor, joined by the palato-pharyngeus, and ends on the superior and 
posterior borders of the thyroid cart, and lateral wall of the pharynx. 



MUSCLES AND FASCTiE OF THE NECK. 163 

The m. pcdato-pharyngeus will be described with the palatal muscles. 

Varieties. — Splitting or doubling or a division into three parte; supernu- 
merary elevators are common, passing to constrictors or fibrous wall of phar- 
ynx; from petrous portion or vaginal process = petro-pharyngeus, from spine of 
sphenoid = spheno-plianjHaeus, from hamular process = ptc rygo-pha ry nyeus ext., 
from basilar process = oceipito-pharyngeus, from mastoid process (rare) = phar- 
yngo-mastoideus ; a small slip to raphe* from pharyngeal spine = azygos-pharj/n<i>s. 

Nerves. — Pharyngeal plexus and motor fibres from bulbar part of sp. access, 
n., glosso-pharyngeal also for mid. constrictor; inf. constrictor has in addition 
fibres from ext. and inf. laryngeal nerve. Stylo-pharyngeus is supplied by 
glossopharyngeal. 

Describe the muscles of the soft palate. 

The soft palate (velum pendulum palati) is continued back from the 
hard palate, pendulous posteriorly, prolonged in the middle into the 
uvula, and laterally into the posterior j)illars of the fauces, which run to 
the side of the pharynx : another fold in front is the anterior pillar of 
the fauces, descending to the tongue ; between them is the tonsil, and the 
constricted part between the anterior pillars is the isthmus of the fauces. 
There are five pairs of muscles — two superior, one intermediate, and two 
inferior. 

The palato-gjossus (constrictor isthmi faucium, glosso-staphylinus) occu- 
pies the anterior pillar of the fauces : at its origin it is below all the 
other palatal muscles, and continuous with its fellow ; inferiorly it enters 
the side of the tongue and joins the transverse fibres. 

M. omygdalo-glossus normally ascends from the side of the tongue to the 
tonsil. 

The palato-pharyngeus (pharyngo-staphylinus) rises by two layers 
which embrace the lev. palati and az.vgos uvulae : the superficial (pos- 
terior) layer is thin, the dee]) (anterior) layer is stronger, meets its 
fellow, and rises in part from the hard palate and apon. of the velum ; 
it receives one or two fibres from the cartilage of the Eustachian tube 
(salpingo-pharyngeus). It passes down in the posterior pillar, mingling 
with the stj^lo-pharyngeus, is inserted into the upper and hinder borders 
of the thyroid cartilage and fibrous hyer of pharynx, passing to or cross- 
ing the median line. 

The azygos uvulae (palato-staphylinus), supposed to be single, consists 
of two slips which rise from the soft palate and posterior nasal spine and 
descend into the uvula, separated above, united below. 

Levator Palati (petro-staphylinus). — Origin, petrous portion of tem- 
poral bone in front of carotid canal, from lower margin of cartilage of 
Eustachian tube, passes forward over the sup. constrictor, and is inserted 
by its fore part into the apon. of the palate, and posteriorly it meets its 
fellow under cover of the azygos uvulae. 

Circumflexus, or Tensor jP«/«^'(spheno-staphylinus). — Origin, scaphoid 
fossa at root of int. pterygoid plate, spine of sphenoid, and outer side of 
Eustachian tube ; descends vertically inside the int. pterygoid muscle : 



164 MUSCLES OF THE TRUNK. 

its tendon turns round the hamular process, where there is a bursa, then 
passes horizontally to its insertion into the transverse ridge of the 
palate bone and apon. of soft palate. 

From before backward in the soft palate is the palato-glossus, tensor 
palati, ant. part of palato-pharyngeus, levator palati, azygos uvulae, post, 
part of palato-pharyngeus, and mucous membrane. 

Nerves. — Sources not fully determined : tensor palati through otic ganglion 
from third division of fifth ; lev. palati, azygos uvulae, palato-glossus, and 
palato-pharyngeus probably by bulbar portion of sp. access, nerve through 
pharyngeal plexus. 

Actions. — The constrictors are nearly immovable behind, and so carry back 
the anterior wall, the hyoid bone and larynx being carried up and back by 
the obliquity of the two lower constrictors. The upper part of the sup. con- 
strictor cannot act directly upon the food, as it is attached at both ends to 
immovable parts. The stylo-pharyngens is the chief elevator of the pharynx 
and larynx; the palato-glossi depress the soft palate, elevate the tongue, and 
shut off the mouth-cavity from the pharynx; the palaio-pharyngei depress the 
soft palate, raise the pharynx, and bring the post, pillars together; the azygos 
uvulae raises and shortens the uvula : the lev. palati raises the palate ; the tensor 
palati tightens and supports the palate against the pull of other muscles and 
opens the Eustachian tube in deglutition. Some hold that the tube is closed 
in deglutition by the lev. palati pressing its floor against its upper and outer 
Avail. The first stage of deglutition is effected by the mylo-hyoid, stylo-glossus, 
and palato-glossus pressing the tongue against the palate ; the hyoid is also 
raised by its elevators ; the larynx is then carried up beneath the hyoid by the 
thyro-hyoid and stylo-pharyngeus, root of tongue is drawn back by the stylo- 
glossi and epiglottis pressed down ; at the same time the soft palate is raised 
and fixed by its proper muscles ; the post, pillars aud uvula shut off the poste- 
rior nares, and the food is guided into the lower pharynx, where it is grasped 
by the constrictors in succession and forced into the oesophagus. 

Posterior Neck-muscles. 

These are divided by the trans, proc. into two groups. The outer 
from the processes to the ribs corresponding to the intercostals, those 
from the processes to the shoulder-blade corresponding to the serratus 
magnus ; the inner group passes from one process to another, long or 
short. 

Outer group, four in number. — 1. M. Scalenus Anticus. — Origin, 
anterior tubercles of trans, proc. of third, fourth, fifth, and sixth cerv. 
vert, ; insertion, by a thick flat tendon into the scalene tubercle and upper 
surface of first rib to neighborhood of the cartilage ; the pleura is at- 
tached to the lower part of the inner surface of this muscle. 

2. M. Scalenus Med ins. — Or if /in, tendinous above, muscular below, 
from posterior tubercles of trans, proc. of all the cerv. vert, (sometimes 
not of atlas) ; insertion, upper edge and outer surface of first rib from 
the tuberosity to the subclavian groove. 

3. M. Scalenus Posticus, smaller than the others. Origin, by two or 
three tendons from the posterior tubercles of the lower two or three cerv. 



MUSCLES AND FASCIiE OF THE NECK. 105 

vert. ; insertion, by an aponeurotic tendon into the second rib external 
to the serratua post. sup. 
Some regard the scalenus mass as one muscle with three insertions. 

Varieties. — A slip from scalenus ant. may pass behind the subclavian artery. 
Scalenus post, may be absent or go to third rib. Scalenus pleuralis, from trans. 
proc. of seventh cerv. vert., spreads out in fascia, supporting the dome of pleura ; 
inserted into inner border of first rib. 

Scalenus minimus and lateralis, the former a slip of the anticus to the first 
rib. the latter of the posticus to the second rib. M. transversal is ceroids 
medius, between the scalenus medius and posticus, connecting the second and 
fourth with the sixth and seventh trans, proc. 

4. M. Levator Scapula? (lev. anguli scapulae). — Origin, by distinct 
slips from the trans, proc. of the upper four cerv. vert, between the at- 
tachments of the splenitis and scaleni ; insertion, posterior border of 
scapula from spine to superior angle. 

Vertebral attachments various : a slip to it from the occipital bone or mas- 
toid process ; parts from vertebras may remain separate to insertion. In 
quadrupeds it unites with the serratus anticus (magnus), and forms one 
muscle; may send a slip to the scaleni, trapezius, serrated muscles, or first 
and second ribs. 

Inner Group. — Long Muscles. — 1. 31. longus colli rests on the front of 
the vertebral column from the atlas to the third dorsal vert. There are 
three sets of fibres : («) vertical part, from bodies of lower two cervical 
and upper two or three dorsal ; on its outer border it receives slips from 
the lower three or four cerv. trans, proc. ; inserted into bodies of second, 
third, and fourth cerv. vert. ; [b) hicer oblique part, from bodies of 
upper two or three dorsal, into anterior tubercles of fifth and sixth cerv. 
trans, proc. ; (c) upper oblique part is the m. longus atlantis of Henle. 
Origin, anterior tubercles of trans, proc. of third, fourth, and fifth 
cerv. vert. ; inserted into the vertical portion and lateral and lower part 
of anterior tubercle on arch of atlas. 

Slip from lower oblique part may be inserted into head of first rib. M. 
transversalis ceroids anticus, from anterior tubercles of trans, proc. of lower 
four cerv. vert, to the body of the axis and trans, proc. of the atlas. 

2. M. Longus Atlantis (see preceding muscle). 

3. 31. Longus Capitis, p. n. (rectus capitis anticus major). — Origin, 
anterior tubercles of trans, proc. of third, fourth, fifth, and sixth cerv. 
vert. ; insertion, basilar process of occipital in front of the foramen mag- 
num ; it may show a tendinous inscription anteriorly ; pharynx is closely 
attached to it. 

Short 3Iuscles. — 1. Mm. Intertransversarii Antei*iores. — Anterior in- 
tertransverse muscles pass as little fasciculi between the anterior tuber- 
cles of the trans, proc. of the cerv. vert. ; they are in front of the nerve- 
trunks. The one for the axis is inserted broadly into its trans, proc. 
They may be lacking for the two upper vertebrae. 

2. 31. Rectus Capitis Anticus, p. n. (rect. cap. ant. minor). — Origin, 



166 MUSCLES OF THE TRUNK. 

front of root of trans, proc. of atlas; insertion, basilar process, between 
foramen magnum and rectus major, 2 inch from its fellow. 

Nerves. — Rectus initials minor by first cerv. nerve ; scaleni and long pre- 
vertebral muscles by neighboring nerves ; the levator scapulae by the third, 
fourth, and fifth cerv. nerves. 

Actions. — The scalene micscles are elevators of the ribs, muscles of inspira- 
tion ; fixed at the ribs are lateral flexors of the neck, or both sides together 
bend it forward ; the recti antici flex the head and throw forward the phar- 
ynx ; the longus colli flexes the neck, and its oblique parts may rotate; the 
levator scapulse elevates the superior angle and base of scapula, counteracting 
the rotation of the trapezius; fixed below, draws neck back and to one side. 

MUSCLES OF THE HEAD. 
Describe the head-muscles. 

These belong to the skull and face ; those of the face are in three 
groups and in three layers. 

Ep icran ia I Muscles. 

M. Epicranius, p. n. (occipito-frontalis), comprises the occipital and 
frontal muscles on either side, united by the Galea aponeurotica. p. n. 
(epicranial apon. ). This covers the upper surface of the skull without 
division, closely attached to integument and loosely to pericranium. 
Behind, it is attached to the occipitales muscles, to the occipital pro- 
tuberance, and supreme curved lines; anteriorly it terminates in the 
frontales; laterally has no distinct margin, but beneath it a thin fascia 
springs from the superior temporal line and passes under the auricular 
muscles to the pinna. The frontalis muscle (m. epicr. frontalis) rises 
from the aponeurosis between the coronal suture and frontal eminence ; 
inferiorly it ends in subcutaneous tissue at the root of nose ( pyramidalis 
nasi is a part of it, Henle), inner canthus of eye, and whole length of 
eyebrow, continued into the pyramidalis nasi and interlacing with the 
corrugator supercilii and orbicularis ; the margins of the right and left 
are united near the root of the nose, but separated higher up. 

The occipitalis 7nuscle (m. epier. occip. ) is attached to the outer two- 
thirds of the superior curved line and to the mastoid process : its fibres, 
1 to 2 inches long, terminate in tendon, and that in aponeurosis; an 
interval between the muscles is occupied by aponeurosis. 

Henle describes the auricular muscles as a part of the epicranius; the 
m. epicr. temporalis is the auricularis anterior of Quain ; rises from the 
root of the zygoma and bony external auditory meatus ; connected with 
the helix and capsule of lower jaw, its fibres pass up and forward to the 
edge of the frontalis muscle and orbicularis oculi, and meet the platysma 
below. 

The m. {epicr.) auricularis superior rises from the Galea apon., and 
converges to the helix by one tendon, and by another to an eminence on 
the inner surface of the pinna. 



MUSCLES OF THE HEAD. 167 

The in. (epicr.) auncalaris posterior rises from the mastoid, sterno-mas- 
fcoid apon., and outer part oil superior curved line, and is inserted into 
the vertical ridge at the back of the concha. All of the ear-muscles are 
more or less connected. 

The post, auricular muscle may rise far back along the superior curved line. 
A deep anterior auricular muscle may pass normally from the zygoma to the 
tragus. 

Actions. — The frontalcs elevate eyebrows, draw scalp forward, and wrinkle 
forehead transversely; occipitales draw scalp back or may alternate with the 
frontales. Most persons have only partial control, best in case of frontalcs. 
The actions of the ear-muscles are slight or nil ; the anterior makes tense tin; 
temporal fascia, and has no effect on the car; they may enlarge the entrance 
to the external ear. 

Muscles of Eyelids and Eyebrow. 

M. orbicularis oculi, p. n., has three parts, is thin and elliptical, covers 
the eyelid, and extends some distance on the forehead, temple, and cheek. 

The pars palpebrals, p. n., is contained in the eyelids, rises from the 
upper and lower margins of the int. tarsal lig., and passes out in a slight 
curve to the ext. tarsal lig. A thicker fasciculus along the free margin 
of each lid is the ciliary bundle. 

The pars orbitalis, p. ??., is larger and stronger, attached to the nasal 
process of the superior maxilla, inner part of orbital arch, and externally 
to the cheek, forming a series of concentric loops. The m. malaris of 
Henle are the lower converging fibres of the orbital part, passing to the 
skin of the cheek and muscles of upper lip. 

The pars lachrymalis, p. n. (tensor tarsi or Horner's muscle), extends 
from the lachrymal crest behind the sac, and divides into two slips be- 
hind the lachrymal canals for the ciliary bundles of the orbicularis. 

The interned palpebral ligament (tendo oculi) is 2 lines long and at- 
tached to the nasal process of the sup. maxilla in front of the lachrymal 
groove ; thence it passes to the inner commissure of the eyelids, split- 
ting and terminating on the tarsi ; it crosses the lachrymal sac in front, 
and gives off a process which passes behind the sac to the crest of the 
lachrymal bone. 

The external pcdpebral lig. is weaker, and attaches the lids to the ma- 
lar bone. 

The corrugator supercilii (described by Henle as a part of the orbic- 
ularis) rises from the glabella, and passes up and out to end at the mid- 
dle of the orbital arch in the orbicularis and skin of eyebrow. 

The levator palpebrce sup. will be described with the orbital muscles. 

Actions. — Palpebral part closes the lids ; upper half of orbital part depresses 
the eyebrow and opposes the frontalis, used in forcible closure of lids; in 
common winking the palpebral part carries forward the int. palpebral lig. 
and anterior wall of lach. sac, and sucks in tears ; the pars lachrymalis (ten- 
sor tarsi) probably alternates with the palpebral part, draws back the palpe- 
bral lig., and compresses the sac. The corrugator produces vertical wrinkles 
at the inner end of the eyebrow. 



168 MUSCLES OF THE TRUNK. 

Muscles of Face. 
First Layer. — In muscular individuals this may be a continuous 
layer under the skin, converging to the corners of the mouth, but it is 
usually divided into — I. M. zygomaticus,from malar bone near zygomatic 
suture to angle of mouth, inserted into skin and mucous membrane by 
two layers, mingling with the levator and depressor anguli oris. 

The so-called zyg. minor is very inconstant, and is best described as a bead 
of another muscle. 

2. M. risorius (Santorini), thin fasciculi from masseteric or parotid 
fascia passing over platysma to skin at angle of mouth ; is not a part of 
the platysma. 

May rise from skin over sterno-mastoid, from zygoma, external ear, or fascia 
over mastoid ; may be double or triple. 

3. M. ti'iangularis menti (depressor anguli oris), from external oblique 
line of lower jaw ; fibres converge partly to skin at angle of mouth, and 
partly to orbicularis of upper lip ; anterior edge is concave and posterior 
convex. 

M, transversus menti, from inner border of the depressor down and in below 
chin, across median line to corresponding point on other side. 

At the corner of the mouth the various decussating muscular fibres give rise 
to a dense mass or knot external to the lip-commissure. 

Second Layer, — 1. M. quadratus labii sup n p. ;?., lies along the 
side of nose from orbit to upper lip, and rises by three heads— caput an- 
gulare, p. w., = levator labii sup. alseque nasi ; caput infraorbital p. n.. 
= lev. labii sup. proprius ; and caput zygomaticum, p. n., =zygomat. 
minor. Caput angulare rises from nasal process of sup. max., generally 
connected with the frontalis, and separates into two fasciculi below — one 
to the skin of the wing of the nose, the other to the skin of the upper 
lip or cheek, blending with the orbicularis oris and the next head. 

The middle head, caput infraorbitals, rises from the anterior surface 
of the upper jaw and its malar process in a line passing from above the 
infraorbital foramen down and out to the suture between the sup. max- 
illa and malar bones, and inserted behind the caput angulare into the 
skin of the wing of the nose and of the upper lip. 

The outer head, caput zygomaticum (zygomaticus minor), rises from 
the tuberosity of the malar, strengthened by bundles of the malaris mus- 
cle, and passes to skin of upper lip and to the caput infraorbitale (lev. 
labii sup. ). 

2. J\I. Caninus (levator anguli oris). — Origin, canine fossa below in- 
fraorbital foramen, covered by the quadratus; passes down and out to 
skin at the angle of the mouth, and a large number of fibres decussate 
with the depressor anguli oris or are continued to the orbicularis of the 
lower lip ; it almost always receives a slip from nasal process of the sup. 
maxilla close under the caput angulare. 



MUSCLES OF THE HEAD. L69 

3, M, Quadratus Menti (depressor labii inferioris). Origin^ lower 
jaw from near symphysis to beyond the menial foramen; passes in to 
its fellow, ami inserted into the skin of the lower lip and orbicularis; it 
is really a continuation of the platysma, 

Third Layer. — Lateral muscles.- .)/. buccinator (trumpet muscle), 
a Hat layer forming a large part of the wall of the mouth ; attached at 

upper and lower margins to alveoli of maxillary bones opposite (lie molar 
teeth, posteriorly to the pteryuo maxillary lig., separating it from the 

superior constrictor of the pharynx; fibres become thickened al angle 

of mouth and join (lie orbicularis; higher and lower fibres are directed 

to corresponding lips, middle ones deoussate, the upper to t he lower lip, 

the lower to the upper lip. 

Median Muscles. — I. Sphincter oris, or m. orhiexdaris oris^ is an ellip- 
tical sheet making the foundation of the lips, composed largely of trans 
verse and vertical fibres from the buccinator and elevators and depressors 
ol* the angle of the mouth; there are also sagittal fibres between the skin 
and mucous membrane. The deeper fibres and a distinct marginal hand 
from the buccinator pass from side to side without interruption ; the le- 
vator and depressor anguli fibres, which have crossed at the corner of 
the mouth, enter the more Superficial parts and are inserted into the 
skin of the middle portion of the lip, mostly after crossing the median 
line and decussating with their fellows; these do not reach the Tree bor- 
der of the lip. 

2. Mm. incisivi attach the orbicularis to hone. The upper lip has (wo 

slips on each side, an outer, or in. indsivus Stip n from the incisor fossa, 
and an inner, m. naso-labialis : from the septum of the nares; the lower 
lip has One fasciculus on a side, m. indsivus inf.. from the incisor fossa. 
These all pass out toward the corners of the mouth. 

The sagittal fibres are more developed in the infant, are in the mar- 
ginal portion, and constitute the m. labii proprius. 

:\. M. iitrsit/fs, p. a., includes slips usually distinguished as compressor 
naris and depressor alai nasi (outer part). 'The former rises from the sup. 
maxilla by the side of the anterior nasal aperture, and meets i(s fellow 
in (he median line over (he cartilages of (he nose in an expansion com 

mon to ii and the pyramidalis nasi. The depressor alovn asi rises from 

(he incisor fossa, and is inserted by its outer part into the back i)\' the 
ala of the nose, and by its inner part into (he septum, called depressor 

s< ph\ ]>. ii. 

The pyramidalis nasi is a prolongation ol' (he frontalis, decussating 

with its fibres, and attached to skin at (he lower median part of the fore 
head and to the tendinous expansion of (he compressor naris below. 

There an 1 other indistinct fibres of nasal muscles the dilator naris 
posh rim- and anterior. 

M. anomalus of Album* is frequently present beneath the common elevator 

of lip and nose (quadratus laiiii sup.), passing from nasal process of sup. mas ilia 

to same hone below, connected witli romp, naris. 



170 . MUSCLES OF THE TRUNK. 

4. M. mentalis, p. ??., levator labii inf. or lev. menti, from incisor fossa 
of lower jaw, passing down between depressors of lower lip to integu- 
ment of chin ; it forms t he furrow of the chin. 

At the apex of the chin between the periosteum and soft parts is some- 
times a bursa. 

M. anomalns menti usually continues the above fibres to the region of the 
mental foramen. 

Nerves. — All the muscles of head and face above described (muscles of ex- 
pression) get their motor supply from the facial ; perhaps the frontalis and 
orbicularis oculi are supplied from the oculo-motor nucleus, and not the 
facial. 

Actions of the nasal muscles are indicated by their names : the pyramidalis nasi 
wrinkles the skin at the root of the nose and draws down that of the fore- 
head ; dilatation of the alae is not usually seen unless in dyspnoea. Of the 
lip-muscles, the orbicularis oris draws the lips together vertically and trans- 
versely and presses them against the teeth; the zyyomaticus draws the angle 
of the mouth up and back ; the risorius retracts the angles of the mouth ; the 
buccinator flattens the cheek, keeps food between the teeth, or expels air from 
the mouth : the levator menti draws up the chin integument, and so protrudes 
the lower lip. Actions of other muscles are indicated by their names ; all 
have to do with the expression of passions. 

Describe the muscles of the orbit. 

There are seven for description. The m. levator palpebrcc superioris 
[origin, above optic foramen and sup. rectus) ends in a membranous ex- 
pansion ; inserted into the fibrous tarsus of the upper eyelid. 

A thin superficial layer is continued over the tarsus to the skin of the lid ; 
some fibres are attached to the conjunctiva, to the wall of the orbit, and to 
the trochlea. 

The four straight muscles have a continuous tendinous origin at the 
apex of the orbit from a ligamentous ring which encircles the optic 
foramen and crosses the sphenoidal fissure ; most of the fibres spring 
from two common tendons: the upper one rises from the inferior root of 
the small wing of the sphenoid, and is prolonged into the internal, supe- 
rior, and external recti; the lower (Zinn) rises from the body of the 
sphenoid and divides into three slips for the internal, inferior, and ex- 
ternal recti. All the recti are inserted into the sclerotic 3 or 4 lines from 
the cornea; the external has two heads, between which pass the third, 
nasal branch of the fifth, the sixth nerve, and ophthalmic vein. The 
external and inferior recti are the longest, internal broadest, and supe- 
rior smallest. 

The superior oblique, or trocldearis, is internal to the lev. palpebrae, 
rises just in front of the optic foramen, and passes forward to a round 
tendon which plays through a fibro-cartilaginous ring attached to the 
trochlear fossa of the frontal : it is there bent out, back, and down be- 
tween the sup. rectus and eye, and is inserted beneath the outer edge 
of the sup. rectus midway between the cornea and optic nerve. The 
pulley is lined by a synovial sheath. 



MUSCLES OF THE HEAD. 171 

The inferior oblique rises from the orbital plate of the sup. maxilla 
close outside the orifice of the nasal duct : the muscle passes out, back, 
and up between the inferior rectus and floor of orbit, and is inserted 
under cover of the ext. rectus at the back part of the eyeball, nearer 
to the optic nerve than to the cornea. 

Varieties. — M. tensor trochleas is a muscular slip from the lev. palpebrre to 
the trochlea ; the occasional gracillimus rises with the sup. oblique and passes 
beneath it to the trochlea ; the ext. rectus may have separate heads to the 
insertion. An accessor;/ inf. rectus may pass from the inf. rectus to the inf. 
oblique ; the transversus orbitx is an arched muscle from the orbital plate of 
the ethmoid across the upper surface of the eyehall to the outer wall of the 
orbit. 

Nerves. — External rectus by the sixth nerve, sup. oblique by the fourth, and 
the other five by the third nerve. 

Actions. — Lev. palpebrse is the elevator of the upper lid and antagonist of the 
palpebral part of the orbicularis. The eyeball seems to move on a central 
fixed point without shifting its place as a whole within the orbit; four move- 
ments are possible: (1) lateral; (2) elevation and depression; (3) oblique 
movements of elevation and depression ; (4) rotation about a sagittal axis. 
The ext. and int. recti produce only lateral movements ; the sup. and inf. recti 
have their line of direction internal to the centre of motion, and so produce 
not only elevation and depression, but also inward direction and slight rota- 
tion : this is corrected by the oblique muscles, the inf. oblique being associated 
with the sup. rectus, and sup. oblique with the inf. rectus; the sup. oblique 
turns the cornea down and out, the inferior up and out. 

Around the orbit is soft fat and the capsule of Tenon, forming a socket at- 
tached in front to the ocular conjunctiva: a large lymph-space is between it 
and the eye ; it is pierced by the eye-muscles and sends a tubular prolongation 
upon each. The suspensory ligament of the eye is a thickening of the lower 
part of the capsule, attached at each end to the orbital margins and support- 
ing the eye in its socket. 

Muscles of Mastication. 

There are four pairs, two outside and two inside the jaw-bone. The 
masseteric fascia is a part of the deep cervical, covers the masseter mus- 
cle, invests the parotid gland (parotid fascia), and forms the stylo-niax- 
illary ligament. 

1. M. masseter, a quadrate muscle with two parts: the superficial part. 
rises from the sup. maxilla, malar, and lower border of zygoma for its 
anterior two-thirds by tendinous bundles which project between the mus- 
cular fasciculi ; it passes down and back to lower half of jaw from angle 
to third molar tooth ; the deep part is triangular, and passes nearly ver- 
tically from the posterior third of zygoma, lower border, and from all 
the deep surface of the arch ; inserted, after uniting with the superficial 
part, into the upper half of the ramus and coronoid : this is almost 
wholly covered by the superficial portion. 

There may be a bursa between these two parts. 

The buccal fat-pad is between the fore part of the masseter and the bucci- 



172 MUSCLES OF THE TRUNK. 

nator, and is prolonged into the zygomatic fossa: it is well developed in the 
infant, and inappropriately called the "sucking pad." 

The temporal fascia is a dense apon. covering the temporal muscle 
above the zygoma: it is attached to the temporal crest of the frontal 
and upper temporal line, and below divides into two layers attached to 
'the inner and outer surfaces of the zygomatic arch ; it is separated from 
integument by a lateral projection of the Galea apon. and by the supe- 
rior and anterior auricular muscles. 

2. M. temporalis rises, fan-shaped, from the whole of the temporal 
fossa, not its anterior malar wall, which is covered with fat, from the 
deep surface of the temporal fascia, and may blend with some deep 
fibres of the masseter. The anterior fibres are nearly vertical, the pos- 
terior nearly horizontal; all converge to a tendon which is inserted into 
the upper and anterior borders of the coronoid, and deeper fibres have 
a fleshy insertion into its inner surface as far as the union of the ramus 
and body of jaw. 

31. temporalis minor occasionally goes from the fibro-cartilage of the temporo- 
maxillary articulation to the sigmoid notch of the lower jaw. 

3. 31. pteri/goideus extermis occupies the zygomatic fossa, and rises by 
two heads, the upper and smaller from the zygomatic surface of the 
great wing of the sphenoid and infratemporal crest; the lower and 
larger from the outer surface of the ext. pterygoid plate. The fibres 
from both pass back, converging to a fossa on the front of the neck of 
the lower jaw, to the interarticular cartilage and capsule. A venous 
plexus is between its upper surface and base, of skull. 

31. pterygoideus propri us is a vertical band from the infratemporal crest out- 
side the ext. pterygoid to the outer pterygoid plate or tuberosity of palate- 
bone or sup. maxilla. 

M. pterygo-spinosns, from the spine of the sphenoid to the outer pterygoid 
plate between the two pterygoid muscles: this is frequently a pterygo-sp'nwus 
ligament, and may be converted into bone. 

4. M. pterygoideus fit tennis rises also by two heads — one from the 
pterygoid fossa, mostly from the inner surface of the external plate, 
from the tuberosity of the palate between the two plates; a second 
small slip outside the ext, pterygoid muscle from the tuberosities of the 
palate and sup. maxilla: fibres pass down, back, and out to the inner 
surface of the ramus between the angle and dental foramen ; it is dis- 
posed much like the masseter. 

Xii res. — All from the inferior maxillary division of the fifth. 

Actions. — 3fasseter, temporal, and int. pterygoid elevate the lower jaw; as de- 
pression is not much resisted, it is accomplished by smaller muscles, chiefly 
the digastric; ext pterygoid protrudes the lower jaw, or alternately produces 
a grinding of molar teeth ; it may also assist in opening the mouth when the 
condyles are carried forward upon the artic. eminences. The hinder portion 
of the temporal and the deep part of the masseter retract the jaw. 



MUSCLES AND FASCIA OF THE EXTREMITIES. 173 

MUSCLES AND FASCIAE OF THE EXTREMITIES. 
The Upper Extremity. 

THE SHOULDER. 
Describe the scapular muscles and fascias. 

The deep fascia is strong and tendinous over the back of the deltoid 
and infraspinatus ; the infraspinatus fascia covers the teres minor and 
splits at the posterior border of the deltoid, a deep layer passing to the 
shoulder-joint under that muscle, a superficial layer to the spine of the 
scapula over the muscle. 

(a) Vertical Scapular Muscles. 

M. Deltoideus. — Origin, in three portions: an anterior from the front 
of the outer third of the clavicle, a middle from the point and outer 
edge of the acromion, a posterior from the lower border of the scapular 
spine and triangular surface at its inner end, and from infraspinatus fas- 
cia. These converge into the tendon of insertion into the deltoid tuber- 
cle of the humerus^ The anterior and posterior parts run by long fas- 
ciculi into the marginal parts of the tendon : in the acromial portion most 
fibres rise in a bipenniform manner from the sides of four tendinous 
septa ; the oblique fibres are inserted below into three septa which come 
up from the humerus to alternate with those above. Some fibres pass 
from the tip of the acromion to the tips of the lower septa, and some 
from the tips of the upper septa directly to the humerus. 

Fibres continued into the trapezius, as in animals lacking clavicles; addi- 
tional slips from ext. or int. border of scapula (basio-deltoideus Meckelii) ; a 
prolongation of its tendon to the insertion of the supinator longus, connected 
inseparably with the pect. major; m. acromio-clavicularis lot. from the acro- 
mial end of the clavicle to the acromion and origin of deltoid ; may be a 
subdeltoid muscle. 

(b) Posterior Scapular Muscles. 

1. M. supraspinatus,from'mnev part of supraspinous fossa to region 
of the notch, from supraspinous fascia and trans, ligament; adherent to 
capsule and infraspinatus tendon ; inserted into the upper of the three 
facets on the great tuberosity of the humerus. 

2. M. infraspinatus rises from the inner two-thirds of the infraspinous 
fossa, from the infraspinatus fascia, and under surface of the spine ; fibres 
converge to a tendon concealed within the muscle and inserted into the 
middle facet of the great tuberosity. It may be inseparably connected 
with the teres minor. 

3. M. Teres Minor.— Origin, from narrow grooved surface or dorsum 
of scapula close to axillary border, from septa between it, the teres 
major, and infraspinatus ; inserted into lowest facet on great tuberosity 
and into shaft for a short distance below. 



174 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

May be a bursa under its insertion. It is behind the long head of the 
triceps and capsule; the dorsal scapular artery passes between it and 
bone. 

(c) Anterior Scapular Muscles. 

M. Subscapulars. — Origin, by muscular and tendinous fibres from 
venter of scapula and groove along the axillary border ; insertion, small 
tuberosity of humerus and into shaft for a short distance. As in the 
deltoid, this muscle contains two sets of septa — one from the origin, and 
one from the insertion for attachment of oblique muscular fibres. Some 
fibres from the axillary border of the muscle are usually inserted into the 
capsule, known as the subscapular is minor. 

There is a bursa between the muscle and the capsule, and often another 
on its anterior surface (bursa coraco-brachialis). 

Nerves. — Supra- and infraspinatus by suprascapular nerve from fifth and 
sixth cervical ; others from post, cord of brachial plexus, detoid, and teres 
minor from fifth and sixth cervical through circumflex nerve; subscapularis 
by fifth and sixth cervical through upper and lower subscapular nerves. 

Actions. — Deltoid abducts arm to 90°, posterior fibres said to abduct only to 
45° ; insertion of trapezius corresponds to origin of deltoid, so that the two are 
continuous in action : anterior part of the deltoid draws the humerus forward 
and rotates in ; of both deltoids crosses the arms over the chest ; posterior part 
draws humerus backward and rotates out ; supra-, infraspinatus, and subscap- 
ularis steady the capsule while deltoid acts. The supraspinatus only abducts. 
The infraspinatus rotates out and carries the arm back when it is raised. The 
subscapularis rotates in and carries the arm forward when it is raised. The 
teres minor rotates the raised humerus out and depresses it. All act as liga- 
ments to the joint. 

THE UPPER ARM. 
Describe the muscles and fasciae of the upper arm. 

The aponeurosis of the arm (deep fascia) is thin over the biceps, strong 
over the triceps, and is attached to the humerus by intermuscular septa 
[ligg. intermuscular id). The external intermuscular septum extends 
from the outer epicondyle and supracondylar ridge to the deltoid inser- 
tion : it is pierced by the musculo-spiral nerve and sup. profunda artery. 
The internal intermuscular septum extends from the inner epicondyle 
and inner supracondylar ridge to behind the coraco-brachialis : it is 
pierced by the anastomotica magna artery. 

The internal brachial lig. of Struthers is a fibrous band below the teres 
major insertion to the inner epicondyle : the ulnar nerve and inf. pro- 
funda artery pass between this band and the int. intermuscular septum. 

[a) Muscles of Anterior Surface. 

First Layer. — M. Biceps (brachii). — Its short or inner head rises with 
the coraco-brachialis from the coracoid ; the long head, from the upper 
end of the glenoid cavity within the capsule by a tendon continuous on 



THE UPPER ARM. 175 

each side with the glenoid ligament: these two heads form a belly in the 
middle and lower part of the arm. The tendon of insertion is slightly 
twisted and attached to the back part of the tuberosity of the radius. 
separated from the fore part by a bursa; may be a second bursa between 
the tendon and ulna. From the inner side of the tendon a part branches 
off as an aponeurotic band or semilunar fascia (lacertus fibrosus, p. ??.), 
and blends with the deep fascia of the forearm stretched across the 
brachial vessels and median nerve. 

One of the most variable muscles: a third head (10 per cent, of cases) rises 
from humerus, connected with brachialis anticus and coraco-brachialis, and 
inserted into coracoid portion of muscle and semilunar fascia: this is usually 
outside the brachial artery ; a head may come from outer side of humerus, 
bicipital groove, or great tuberosity ; may be two additional heads or even 
three. It may give off a slip to the internal intermusc. septum or inner con- 
dyle or pronator teres. Absence of long head : it was originally extracapsu- 
lar, but has become covered by the coraco-humeral lig., a part of the pect. 
minor. The semilunar fascia represents an ulnar division and corresponds 
to the fascial insertion of the biceps fern. 

Second Layer. — 1. M. Coraco-brachialis. — Origin, tip of coracoid 
between pect. minor and short head of biceps, conjoined with the latter ; 
insertion, inner border of humerus near its middle, between triceps and 
brachialis anticus ; higher up some of its fibres are often inserted into a 
fibrous band arching over the lat, clorsi and teres major tendons, and at- 
tached close to the small tuberosity. It is usually pierced by the mus- 
culocutaneous nerve. 

Many varieties, which seem to indicate it is formed of three parts — viz. (1) 
a superior short part, from coracoid to small tuberosity (m. coraco-capsidaris to 
capsule) ; (2) middle part, corresponding to the muscle usually seen ; (3) infe- 
rior part, to inner epicondyle or supracondylar process (coraco-brachialis minor). 
The middle part is most constant in man, but is usually accompanied by a 
part of the third, with the musculo-cut. nerve between them. It may send a 
slip to the brachialis anticus or internal septum or int. brachial lig. 

2. M. brachialis anticus (brachialis internus, p. n.) rises from the 
lower half of the front of the humerus, nearly the whole of the int. 
intermuscular septum, and upper part of the external : it embraces the 
deltoid insertion by two processes, the outer of which is in the spiral 
groove as far as the upper limit of the deltoid tubercle. It is adherent 
to the capsule of the elbow-joint, and often sends a slip into it, and is 
inserted into the inner part of the rough surface at the junction of the 
coronoid with the shaft of the ulna. 

The muscle may be subdivided into two. united with neighboring muscles, 
or send a slip to the semilunar fascia or radius. 

(b) Posterior Muscles of the Upper Arm. 

M. extensor triceps occupies the whole posterior brachial region. Three 
heads are inserted into a common tendon occupying the posterior surface 



176 MUSCLES AND FASCIA OF THE EXTFvEMITIES. 

of the muscle from the middle of the arm to the elbow. The middle or 
lout/ head (anconeus longus — anconeus was a term applied to any muscle 
attached to the olecranon) rises from the inf. glenoid tubercle of the 
scapula and adjacent portion of axillary border : this forms the middle 
and superficial part of the muscle and ends on the inner margin of the 
tendon. The external head (anconeus brevis) rises above the spiral 
groove and from an aponeurotic arch of the external intermusc. septum 
as it crosses it, extending to the teres minor insertion above, and inserted 
into the upper end and outer border of tendon. The internal or deep 
head (anconeus interims) rises from the whole posterior surface of the 
humerus below the spiral groove, from the lower part of the external in- 
termusc. septum, from the whole of the internal, as high as the teres major : 
some of its fibres are inserted directly into the olecranon, but most join 
the deep surface of the tendon. The common tendon is inserted into the 
tuberosity of the olecranon, and externally a band is prolonged over the 
anconeus to the fascia of the forearm and posterior border of ulna : it 
may send a slip to the capsule. 

On removing the triceps a few muscular slips are sometimes found 
from the bone to the capsule, analogous to the subcrureus,and described 
by some as distinct from the triceps called the subanconeus. 

There is a bursa between the tendon and olecranon or in the tendon, 
sometimes one between the integument and tendon, rarely one between 
the tendon and ulnar nerve (retro-epitrochlear). 

Varieties. — Fourth head from inner part of humerus ; a slip between triceps 
and lat. dorsi, the anconeus quintus or dorso-ejntrochlearis of animals; the an- 
coneus-epitrochlearis from the inner epicondyle to the olecranon, bridging over 
the ulnar nerve and generally present as a band of fascia. 

Nerves. — Coraco-brachialis by branch from outer cord (7 c), biceps by mus- 
culo-eut. (5, 6 c), brachialis anticus by mnsculo-cut. and musculo-spiral, tri- 
ceps by musculo-spiral (7, 8 c). 

Actions. — Biceps flexes arm at shoulder and forearm at elbow; after prona- 
tion of forearm it is a powerful supinator and makes tense the fascia of the 
forearm ; its inner head and coraco-brachialis draw arm in as well as up. The 
brachialis anticus is a simple flexor at the elbow. Triceps, int. and ext. heads 
are extensors at the elbow; the long head extends the arm on the scapula, 
keeps the head of humerus in place, and assists in extending the forearm. 
These muscles may act from distal fixed points, as in climbing. 

THE FOREARM. 

Describe the muscles and fasciae of the forearm. 

The superficial fascia is most distinct at the elbow, contains the super- 
ficial veins, and below connects the skin with palmar fascia. 

The aponeurosis of the forearm (deep fascia) is composed largely of 
transverse fibres, strengthened by expansions from the condyles of the 
humerus, olecranon, and fascia over biceps and triceps. The anterior 
part is weaker than the posterior, and continuous below into the ant. 
annular ligament (lig. carpi volare, p. n. ) : it sends in a thin layer be- 



THE FOREARM. 177 

bween the superficial and deep muscles. The posterior portion sends 
oft' septa between the muscles and forms the post, annular ligament (lig. 
carpi dorsale, p. n.). 

Anterior Group, Pronato-flexor. 

Bight muscles, five superficial and three deep. 
Superficial Layer. — All from a common tendon in the following 
order from without in : 

1. Jf. pronator teres rises by two heads, the larger from the upper 
part of the inner condyle, common tendon, fascia, and intermuscular 
septum : second head, thin and deep, from inner margin of coronoid ; 
insertion, middle of outer surface of radius. The ulnar artery is beneath 
this muscle, and median nerve between its heads. 

Liable to be injured in the "back stroke" of lawn tennis. Coronoid head 
maybe absent; slip from intermusc. septum above inner condyle or from 
supracondylar process; additional head from biceps or brach. anticus. 

2. 31. flexor carpi radialis (m. radialis internus) rises from the com- 
mon tendon, fascia of forearm, and septa between it and the pron. teres, 
palmaris longus, and flex, sublimis ; tendon begins below middle of fore- 
arm, passes through a special compartment of the ant. ann. lig., through 
a groove in the trapezium ; inserted into the base of the second meta- 
carpal bone, anterior surface, and usually by a small slip to the base of 
the third. 

Absence of muscle ; inserted into ann. lig., trapezium, or fourth metacarpal ; 
receives slip from biceps or its fascia, coronoid process, or oblique line of 
radius. 

3. M. palmaris longus is placed between the ulnar and radial flexors 
of the carpus, resting upon the flex. subl. ; rises from common tendon, 
fascia, and septa, forming a short muscular belly ending in a slender 
tendon, inserted into the palmar fascia, and sends a slip to the abductor 
poll. , sometimes one to the little finger muscles. 

Most variable muscle of body, lacking on both sides in one-third of the cases, 
on one side in one-half the cases (Hallett). Muscular belly may occupy the 
middle of the tendon, lower end, both ends, or be absent; may be double or 
have additional origin from coronoid or radius. Inserted into fascia of fore- 
arm, flex, carpi uln., pisiform, scaphoid, or little finger rrfliscles. This muscle 
with the central part of the palmar fascia w r as a superficial flexor of the 
fingers, but has been reduced by the development of the other flexors. 

4. M. flexor carpi vlnaris (m. ulnaris int.) is the innermost of the 
superficial group ; rises by two heads, one from the common tendon, and 
one from the inner side of the olecranon and upper two-thirds of the 
post, border of the ulna, connected with the deep fascia of the forearm ; 
muscular fibres end in a tendon along its anterior margin ; inserted into 
the pisiform, by a small band to the ant. ann. lig., and prolonged by the 

12— A. 



178 MUSCLES AND FASCIJ3 OF THE EXTREMITIES. 

piso-metacarpal and piso-uncinate ligaments to the fifth metacarpal and 
unciform. 

The ulnar nerve and post, ulnar recurrent artery pass between its two 
heads : the pisiform throws this tendon forward, so that the ulnar pulse 
cannot be felt so well as the radial. 

Additional slip from corouoid; insertion into aim. lig. or fourth and fifth 
metacarpals. Monro thinks there is a bursa between its tendon and the 
pisiform. 

5. M. flexor sMimis digitorum (perforatus), placed behind the pre- 
ceding, rises by three heads: (1) inner condjde by common tendon, fibrous 
septa, and int. lateral lig. ; (2)inner margin of coronoid ; (3) ant. oblique 
line of radius; divided below into four parts ending in tendons inserted 
into the second phalanges of the four inner digits. Through the ann. 
lig. they are placed in pairs : the anterior pair are for the ring and mid- 
dle fingers, the posterior for the index and little fingers. In the palm 
they diverge and enter a sheath with the flex. prof. ; opposite the bases 
of the first phalanges the tendon divides and folds round the deep flexor, 
and is reunited behind it ; the two portions again separate and pass on 
each side to the middle of the lateral border of the second phalanx. 

The arrangement into pairs corresponds to a division into layers, which can 
be separated nearly to tbe inner condyle; the middle finger receives the 
radial head, the ring-finger tendon is joined by a slip from the deep layer; 
this deep layer is a digastric muscle from the inner condyle, int. lat. lig., and 
corouoid; the conical belly ends in a tendon above the middle of the fore- 
arm, from which rise (1) a fleshy slip to the ring-finger tendon, (2) a belly 
for the index-finger tendon, (3) small belly furnishing the little-finger ten- 
don. There is usually a slip from the condylo-ulnar head to the flex. long, 
poll, tendon. 

Varieties. — Absence of radial head; of little-finger portion, which may be 
replaced by a slip from ann. lig., palmar fascia, flex, prof., or fourth lumbri- 
calis ; a frequent slip to the flex. prof. A bursa in its tendinous origin or be- 
tween it and the pron. teres in 1 per cent, of cases. 

Deep Muscles. 

First Layer. — 1. M. flexor profundus digitorum (perforans). — Origin 
(not from humerus), three-fourths of inner and anterior surface of ulna, 
from not quite the ulnar half of the interosseous membrane for the same 
distance, and from an apon. attached to the post, border of the ulna, com- 
mon to it and flex. c. ulnaris. Only one tendon (for index finger) sep- 
arates above the wrist ; in the palm, as the tendons diverge, they give 
origin to the lumbricales ; over the firsthand second phalanges the tendon 
is bound down by an osseo-aponeurotie sheath, and opposite the first 
phalanx it passes through an opening in the flex. subl. tendon, and is 
finally inserted by an expanded end into the base of the last phalanx : 
over the middle and last phalanx its tendon is marked by a longitudinal 
furrow or cleft. 

The index-finger portion is usually separate throughout, and comes mostly 



THE FOREARM. 179 

from the interosseous membrane ; between the ring- and little-finger portions 
8 considerable part of the inner surface of the ulna is free from muscular at- 
tachment. 

M. aeces8orius, from the common tendon of the superficial muscles. 

The sheaths of the fleocor tendons are opposite the first and second 
phalanges, and formed of strong transverse bands, ligg. vaginalia; op- 
posite the joints the bands change into a thin membrane, strengthened 
by oblique decussating fibres, so that there are annular or transverse 
fibres, crucial and oblique. The sheath has a synovial lining containing 
small folds, vinculo tendinum or ligg. mucosa, passing between tendons 
and bones. There are two sets : ligamcnta brevia. broad, four-sided, 
and membranous, passing between both the superficial and deep tendons 
near their insertions and the lower part of the phalanx just above the 
joint-capsule ; the ligamcnta longa, less constant, join the tendons at a 
higher level. Contained in the lig. breve of the deep flexor is a small 
band of yellow elastic tissue, lig. subflavum, passing from the tendon to 
the head of the second phalanx. 

2. M. flexor longus poll ids rises from the anterior surface of the radius, 
from its oblique line to the edge of the pron. quad., and from the adja- 
cent part of the interosseous membrane, and usually (27 out of 36 cases) 
receives a slip (fasciculus exilis) from the inner epicondyle or coronoid. 
The tendon passes between the sesamoid bones of the thumb and enters 
a canal similar to that of the other flexors, to be inserted into the base of 
the last phalanx of the thumb. Its complete separation from the flex, 
prof, is characteristic of man. 

May have a slip from flex. subl. or prof, or pronator teres ; may be inserted 
into index finger or first lumbricalis. 

M. flexor carpi radialis brevis or profundus (6 out of 70) rises from outer sur- 
face and anterior border of radius between insertions of pron. teres and supi- 
nator longus; insertion, very variable into tendon of flex c. rad. or bones of 
carpus or metacarpus ; more often present in the right arm. 

M. ulnaris int. brevis (m. flex. c. ulnaris brevis) is a corresponding muscle 
from lower fourth of anterior surface of ulna to unciform. 

Second Layer. — M. pronator quadratics, close to bones behind the 
last, two muscles, quadrilateral and flat, from pronator ridge and inner 
part of anterior surface of ulna for lower fourth, from radio-carpal joint ; 
inserted into fore part and inner side of radius for less than its fourth. 

May be absent, subdivided into two or three layers, extended further up than 
usual, prolonged down as radio-carpal or ulno-carpal muscle ; a slip from ulna 
to trapezium or scaphoid = m. cubito-carpeus. Being bound to radio-ulnar 
capsule, it prevents its folding in pronation movements. 

Nerves. — Six and one-half of the above muscles by the median nerve, one 
and one-half by the ulnar. Pron. teres, flex. c. rad., palm, longus, condylo- 
ulnar head of flex. subl. receive median branches near elbow ; radial head of 
flex. subl. and belly for index finger have separate twigs ; flex. long, poll., pron. 
quad., and outer half of flex. prof, by ant. interosseous br. of median. Flex, 
c. ulnaris and inner half of flex. prof, by ulnar. 



180 MUSCLES AND FASCIJE OF THE EXTREMITIES. 

Radial Group. 
Three in Dumber, from lower third of arm and upper third of forearm 
in an almost continuous row. 

1. 31. supinator longus (brachio-radialis) rises from the upper two- 
thirds of the ext. supracondylar ridge of the humerus and ext. inter- 
muscular septum, limited above by the spiral groove : thin fleshy belly 
ends at middle of forearm in a flat tendon which expands at its insertion 
into the outer side of the radius at base of stjdoid process; its inner edge 
is united by fascia to the flex. c. rad. ; it sends some fibres to the apon- 
eurosis on the back of the forearm. 

Muscle doubled or absent ; united with brach. anticus ; tendon splits into 
slips inserted together or at a distance from each other ; inserted into middle 
of radius, tendon of biceps ; slips to extensors of thumb. 

31. sup. long, accessorius (1 per cent, of cases) rises either above or below the 
origin of the normal muscle and passes between it and the mm. radiales to 
the tuberosity of the radius. 

2. 31. extensor carpi radial is longior rises from the lower third of the 
ext. supracondylar ridge and ext. intermusc. septum and a few fibres 
from the common tendon ; inserted into base of second metacarpal. 

3. 31. Extensor Carpi Radicdis Brevior. — Origin, by common extensor 
tendon from outer condyle, septa, ext. lat. lig. , fascia, and a fibrous arch 
over the radial n. and rad. recurrent vessels ; insertion, base of meta- 
carpal bone of middle finger. 

Where these tendons are crossed by the first two thumb extensors a bursa 
is interposed ; there is another under each tendon at its insertion ; often one 
between the short rad. extensor and supinator brevis. 

Each tendon may be split into two or three at its insertion ; either may be 
inserted into both the second and third metacarpals or send a slip to the 
fourth. The two muscles may be united more or less completely. 

31. extensor c. rad. intermedins, from humerus or normal extensors to second 
and third metacarpals or both. 

31. extensor c. rad. accessorius, from humerus near attachment of long radial 
extensor, inserted by two slips into abd. poll, or first dorsal inteross. and into 
metacarpal bone of thumb. 

Posterior Group. 

Two layers, muscles of superficial layer inserted into ulnar edge of 
forearm and hand and into fingers from fifth to second inclusive ; of deep 
layer into radial edge of forearm and hand and two outer fingers. 

Superficial Layer, — 1. 31. Extensor Communis pigitorum. — Origin 
(from neither ulna nor radius), common tendon, fascia, and septa ; there 
are three fleshy bellies, the innermost divided into two, four passing under 
the post. aim. lig. ; the first and second pass to the index and middle fin- 
gers connected by a weak band, always transverse ; the first is joined by 
the extens. indicis tendon at the metacarpophalangeal joint ; the third 
runs to the ring finger and sends a slip to the middle finger tendon ; the 
fourth divides, the outer larger part going to the ring finger, the inner 



THE FOREARM. 181 

part joining the outer division of the extens. min. dig. tendon : this 
fourth is the smallest tendon, and receives muscular fibres as far as the 
wrist. 

Opposite the metacarpophalangeal joints the tendons are bound down 
by transverse fibres from the front of the joint, ligg. dorsalia; the tendon 
expands, is joined by a slip from the interossci, and on the radial side by 
the insertion of a lumbrical muscle, forming a broad aponeurosis, which 
divides at the lower part of the first phalanx into three slips — a central 
thin one for the base of the second, while the two lateral parts join and 
are inserted into the base of the last phalanx. 

Varieties. — Deficiency of one or more tendons, especially for fifth finger; 
more often an increase, especially for the index and middle fingers ; a doub- 
ling or tripling of all the tendons ; a slip to the thumb. 

2. M. extensor minimi digiti (extens. dig. quinti propr.) rises from 
superficial and deep fascia of forearm, from septa between it and the 
common and ulnar extensors: its tendon is in a groove between the 
radius and ulna, and splits into two on the back of the hand, the outer 
being joined by a slip from the fourth common extens. tendon, and both 
parts end on the little finger, like the other extensor tendons. 

Rises by a thin slip from the common tendon in 5 per cent, of cases ; tendon 
of insertion undivided in 10 per cent, of cases; gives a slip to ring finger in 
6 per cent. ; fusion of belly with common extensor in 4 per cent. ; absence 
rare. 

3. M. Extensor Carpi Ulnaris (ulnaris externus). — Origin, common 
tendon, septa, fascia of forearm, which is connected with elbow-joint 
capsule and anconeus ; its belly in its middle third is bound to the pos- 
terior border of the ulna by aponeurosis, and may receive fibres from 
this fascia; insertion, tuberosity of base of fifth metacarpal. A bursa 
is under its tendon of origin in one-fourth of the cases. 

In 52 per cent, of cases a slip is continued anteriorly over the oppo- 
nens min. dig. to the fascia over that muscle, to the metacarpal bone or 
first phalanx of the little finger (analogue of per. brevis of little toe). 

Muscle may be double, reduced to a tendinous band, inserted into fourth 
or third metacarpal. 

M. ulnaris quinti digiti, from post, surface of lower half of ulna to base first 
phal. of little finger : is represented in 44 per cent, by a dorsal slip from ex- 
tens, uln. tendon to metacarpal bone, or first phal. or extens. tendon of little 
finger. 

4. M. anconeus (quartus) fills the space between the triceps and extens. 
carp. uln. ; is flat and triangular, covered by fascia connected with the 
triceps ; rises by a narrow tendon from a fossa on the inner and posterior 
part of the ext, condjde ; upper fibres are transverse, rest pass obliquely 
down and in to the radial aspect of the olecranon and adjacent upper 
third of the ulna. As a rule, its superior fibres are continuous with 



182 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

those of the int. head of the triceps. A bursa is found under its tendon 
of origin, not in children. 

Deep Layer.— 1. 31. Supinator Bran's. — Origin, ext. lat. lig., 
orbicular lig., supinator ridge, bicipital hollow of ulna, and for a short 
distance on outer border of ulna, from fascia covering it, which is con- 
nected with the ext. condyle: it regularly consists of two layers separated 
by the post, interosseous n. ; fibres pass sling-like around upper part of 
radius to be inserted into a third of its length, limited by the ant. and 
post, oblique lines, to its neck and elbow-joint capsule. 

Anterior fibres may have separate insertion into the orbicular lig.; inser- 
tion into biceps or tuberosity of radius. 

2. M. Extensor Ossis Metacarpi Pollicis (abd. poll, longus). — Origin, 
upper part outer division of posterior surface of ulna below supinator 
brevis, from middle third of posterior surface of radius and interosseous 
membrane between ; inserted into radial side of base of metacarpal bone 
of thumb, and commonly by a slip into the trapezium, its tendon usually 
splitting. 

3. 31. extensor longus pollicis (ext. secundi intern, poll.) rises below 
the extensor ossis on the middle third of the ulna and from the inteross. 
memb. for about 1 inch : its tendon passes over the radial extensors, and 
is inserted into the base of the last phalanx of the thumb. There is a 
tendency for it to divide into three parts, as in case of extensor comrn. 
tendons, but all three converge to the base of the last phalanx. 

4. M. Extensor Indicis Proprius (m. indicator). — Origin, from ulna 
below extensor long. poll. , and slightly from interosseous membrane and 
fascia over extens. c. uln. ; unites with the common extensor tendon for 
the index, and forms the usual insertion. This and the ext, min. dig. 
tendon are always on the ulnar side of the common extensor tendons. 

Earely absent, often double, and one slip may pass to the thumb, ring 
finger, or middle finger, forming an extensor medii digiti which can rise sepa- 
rately from the ulna or post aim. lig. 

M. extensor brevis dig. mantis, from back of wrist-joint, carpus, or metacarpus, 
sending tendons to one, two, or three fingers. 

5. 31. Extensor Brevis Pollicis (ext. primi internod. poll.). — Origin, 
small part of inteross. memb. and radius below the middle, next below 
the extensor ossis ; insertion, proximal end of first phal. of thumb. 

Varieties in thumb extensors in 1 out of 6 cases ; most often in extens. 
ossis; insertion into short thumb-muscles. Extens. brevis poll, is peculiar to 
man, lacking in 5 per cent., fused as it were with the extens. ossis ; it may be 
united with the long extensor. The long extensor is often double ; may send 
a slip to the common extensor or indicator. May be another extensor between 
the indicator and extens. long, poll., with insertion into both digits; this is 
normal in the dog. 

Nerves. — For the radial and posterior groups wholly by the musculo-spiral ; 
the anconeus, sup. longus, and extens. carp. rad. long, by that nerve before it 
divides; all the others by its post, interosseous branch. 



THE HAND. 183 

Three nerves, therefore, supply all the muscles of the forearm— median and 
ulnar anteriorly (flex. C. nln. and inner half of flex. prof, by ulnar), musculo- 
ipirai externally and posteriorly. 

THE HAND. 
Describe the muscles and fasciae of the hand. 

Fascia of tlie dorsum is a thin layer prolonged from the post. ami. 
lig. and blending with the extensor expansions over the fingers; deeper 
'than this the interossei are covered by thin aponeuroses. 

Fascia of the palm (volar aponeurosis) consists of a strong central 
part and two lateral portions which cover the short muscles of the thumb 
and little finger. The central portion is the part commonly called pal nan- 
fascia : it consists of fibres mostly prolonged from the palm, long., some 
from the ann. lig., thus forming two superficial layers with vertical fibres, 
between which is the palm, brevis muscle ; there is a deep layer of 
transverse fibres. Below the fascia divides into four processes to join 
the digital sheaths ; offsets are sent back to the deep trans, lig. at the 
heads of the metacarpals, forming a short canal above each finger for 
the flexors. Between the processes the transverse layer of fascia covers 
the lumbrical muscles, digital vessels, and nerves, passing over to the 
thumb and forefinger. At the clefts of the fingers a transverse band 
is called the superficial trans, lig., or Gerdy's fibres. The interossei 
muscles also have a separate fascia continued below into the deep trans, 
lig. 

(a) On the Dorsum. 

Extensor tendons already described. 

(b) Muscles of Volar Surface. 

Superficial Muscles. — M. palmaris brevis, thin and subcutaneous, 
rises from ann. lig. and deep layer of longitudinal fibres of palmar fascia, 
and ends in a vertical line in the fascia covering the ball of the little 
finger, and sometimes in the skin. 

Deep Muscles. — Median. — Carpal Bursa?. — As the superficial and 
deep flexors and flex. long. poll, enter the hollow of the hand they are 
bound into one tube lined by synovial tissue; a loose synovial sac is 
formed, passing up to the level of the radio-carpal joint and prolonged 
down the inner tendons to the digital sheath of the little finger, open- 
ing into it generally. The sheath for the tendon of the thumb is gen- 
erally separated from the large sac by a sagittal septum behind the me- 
dian nerve ; the bursa extends but a short distance on the index and 
middle-finger tendons. 

The mm. lumbricales (fiddler's muscles) are four tapering fasciculi 
passing from the deep flexor tendons each to the dorsal expansion of the 
common extensor on the radial side of the first phalanx: each rises 
from the radial side and radial part of the ant. surface of the deep 



184 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

flexors, and the inner two also from their ulnar borders — 1. c. have two 
heads. 

Varieties. — A diminution or increase : one finger may have two inserted 
into it: the fourth may take the place of the fourth superficial flexor. 

Muscles of the Ball of the Thumb. — These constitute the thenar emi- 
nence; great variety of description. (See Quain and Ilenle.) 

1. M. Abductor Ppllicis (brevis). — Origin, front of ann. lig., ridge of 
trapezium or tuberosity of scaphoid ; insertion, base of first phal. of 
thumb, radial border, and sends a slip to the extensor tendons. (Henle 
calls this one belly, and what is described below as the outer head of the 
flexor brevis he calls the other belly of the abductor). 

2. M. Flexor Brevis Pollicis. — Outer or superficial head from outer 
two-thirds of ann. lig. to outer side of base of first phalanx, having a 
sesamoid bone developed in it: inner or deep head is very small, and 
between the add. obliquus and outer head of first dorsal interosseous ; 
rises from ulnar side of the first metacarpal ; inserted into inner side of 
base of first phalanx. 

3. M. adductor pollicis Quain describes in two parts, separated by the 
radial artery as it enters the palm. The adductor obliquus poll ids (caput 
obliquum, p. n.\ largest of thumb muscles, rises from the upper ends 
of the second and third metacarpals, os magnum, ant. carpal ligaments, 
and sheath of flex. c. rad. : it passes on the inner side of the long flexor 
tendon to the inner side of the base of the first phalanx, uniting with 
the adductor transversus and deep head of flexor brevis. The inner 
sesamoid bone is deyeloped in it. A considerable fasciculus passes be- 
hind the long flexor to join the superficial head of the flexor brevis and 
outer sesamoid bone. (This muscle is usually described as the inner 
head of the flexor brevis. ) 

The adductor transversus poll, (caput transversum, p. n.) rises from 
the lower third of the front of the third metacarpal bone ; inserted into 
inner side of base of first phalanx of thumb, and the common insertion 
sends a slip to the long extensor. 

4. M. opponens pollicis, beneath the abductor, rises from the ann. lig. 
and outer side of ridge of trapezium ; inserted by an upper layer into 
the whole length of the first metacarpal bone, radial border, and by its 
deeper layer into the head of the bone and radial part of its palmar 
surface. 

Muscles of Ball of Little Finger. — These three muscles constitute the 
lujpothenar em inence. 

\. 31. abductor minimi die/it i (abd. dig. quinti) rises from the lower 
border and inner surface of the pisiform, almost a continuation of the 
flex. c. uln. ; insertion, base of first phalanx of little finger, ulnar side, 
and into a sesamoid bone, sending a slip to the extensor tendon. 

2. M. flexor brevis min. dir/iti is separated from the abductor by deep 
branches of the ulnar nerve and artery, and nses from the annular lig. 
and tip of unciform process ; inserted into the base of the first phalanx 



THE HAND. 185 

by means of a tendinous arch passing over the flexors, attached to the 
radial and ulnar borders of the base. May be absent or fused with the 
abductor. 

3. M. opponent minim! digiti. from aim. liir. and unciform process to 
whole length of ulnar side of fifth metacarpal and anterior surface of its 
head. 

Mm. Interossei. — The dorsal interossei are four in number, one for 
each space, not rising above the level of the bones, and numbered from 
without inward. Each rises from the two bones between which it is 
placed, most extensively from that supporting the finger upon which it 
acts. The tendon is inserted partly into the base of the first phalanx 
and partly into the extensor tendon : they abduct the fingers from the 
middle line ; two are inserted into the middle finger, one on either side, 
one into the radial side of the index, and one into the ulnar side of the 
ring. The first dorsal interosseous is larger than the others, called the 
abductor indicis: its outer head comes from the proximal half of the 
ulnar border of first metacarpal, its inner from the whole length of the 
radial border of second metacarpal. 

The palmar interossei are three in number, are adductors, and each 
rises from the lateral surface of the metacarpal of the finger on which it 
acts. They terminate like the dorsal tendons. The first belongs to the 
ulnar side of the index, the second and third to the radial sides of the 
ring and little fingers. Henle describes four palmar interossei, the 
first being the inner head of the flex, brevis poll. , as described above. 
Small bursae are between the interossei tendons and metacarpo-phal. 
joints. 

Varieties. — Palm, brevis seldom absent: a slip to abd. poll, from skin over 
thenar eminence ; abductor divided into outer and inner parts, accessory head 
from parts above ; abductor min. dig. divided into two or more slips, or acces- 
sory head from above ; may be inserted into fifth metacarpal, representing the 
m. pisi-mctacarpeus ; there may also be the m. pisi-uncinatus and m. pisi-an- 
nularis. 

Nerves of Hand-muscles. — Abductor poll., opponens poll., outer head of flexor 
brevis poll., and outer two lumbricales (outer three, Ziemssen) are supplied 
by the median nerve. The palm, brevis, muscles of little finger, inner two 
lumbricales (fourth, Ziemssen), all the interossei, adductores poll., inner head 
of flex. brev. poll., are supplied by the ulnar nerve. 

Actions of Muscles of Forearm and Hand. — Pronation by pronator teres and 
quadratus and flex. c. racl. slightly; pron. teres flexes forearm ; can only pro- 
nate when radius is intact. 

Supination by supinator brevis, biceps, and sup. longus ; the latter is a flexor 
of the elbow and brings the forearm into mid-supination. Radial extensors of 
wrist flex elbow; others from the ext. condyle extend. Flexion of wrist by 
flex. c. uln. and rad., by flexors of fingers, and palm, longus. 

Extension of wrist by extens. c. uln., the two radial extensors, and exten- 
sors of fingers. 

Abduction of wrist by radial flexor and radial extensors and extensors of 
thumb. 

Adduction of wrist by the flexor and extensor c. uln. The flex. c. rad. and 



186 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

extcns. c. uln. act on the radio-carpal joint ; the flex. c. uln. and radial exten- 
sors on the mid-carpal joint. 

The extensors of the wrist are moderators of the long flexors of the fingers; 
the flexors of the wrist are moderators of the extensors of the fingers. 

The dorsal interossei abduct the fingers from the middle one; the palmar 
adduct ; the interossei and lumbricales flex the first phalanx and extend the 
last two (a movement in forming the hair-stroke in writing). 

Flexion in Fingers. Extension in Fingers. 

1st phalanx, by interossei and lumbricales. By extensor communis. 

2d phalanx, by flexor sublimis. By interossei and lumbricales. 

3d phalanx, by flexor profundus. By interossei and lumbricales. 

When we flex fingers they tend to approach, due to lat. ligaments and obliq- 
uity of tendons. 

The palmaris longus makes tense the palmar fascia, feebly flexes forearm 
and wrist; all the muscles from the inner condyle feebly flex forearm. 

Palmaris brevis wrinkles the skin over the hypothenar eminence and pro- 
tects the ulnar vessels and nerve from pressure when a foreign body is 
grasped. 

Extension in the thumb is in the plane of abduction of the fingers, and its 
abduction is a movement forward. The action of its muscles and those of the 
little finger are indicated by their names: the flexors of the first phalanx in 
either case also extend the last, as the interossei would. The ulnar extensor 
and flexor of the carpus are moderators of the thumb extensors. There are 
three flexors of the wrist (including palmaris long.) and three extensors, 
three flexors of fingers and three extensors, three flexors of thumb and three 
extensors. 

Muscles and Fasciae of the Lower Extremity. 

THE HIP AND THIGH. 
Describe the fasciae of hip and thigh. 

The superficial fascia is continuous with that of other parts of the 
body. Thick over gluteal region, passes over Poupart's ligament into 
dartos of scrotum and superficial fascia of perineum. A deep layer of 
this fascia is continued across the saphenous opening, perforated by ves- 
sels and lymphatics, cribriform fascia. 

The deep fascia or fascia lata is a strong membrane forming a continu- 
ous sheath around the limb : it is attached above to back of sacrum and 
coccyx, crest of ilium, Poupart's ligament, body and rami of pubis, ramus 
and tuberosity of ischium, and lower margin of great sacro-sciatic liga- 
ment. It descends on the glut, medius as fir as the upper border of the 
glut, max., which muscle it encases, and" over the great trochanter a 
great part of the muscle is inserted between its layers. From the fore 
part of the iliac crest to the outer tuberosity of the tibia is the ilio-tibial 
band, which receives the tensor vag. fern, and glut. max. insertions. 

The fascia is thinnest at the inner part of the thigh over the adduc- 
tors, and strengthened on each side of the patella by expansions from 



THE HIP AND THIGH. [87 

the vasti. Posteriorly it is continuous over the hamstrings and popliteal 
space. 

On the front of the thigh, below the inner end of Poupart's ligament, 
is the saphenous opening^ bounded externally by the falciform l><>r<hr 
(ligament of Burns), more distinctly curved above and below as sup. 
and inf. cormia. The inner extremity of the sup. cornu passes to the 
inner side of the fern, sheath and to Gimbcrnat's ligament: it is the 
femoral ligament (Hey). 

The parts external and internal to the saphenous opening are the iliac 
and p>ul>ic portions ; the iliac is connected above with Poupart's and the 
deep layer of superficial fascia (of Scarpa), and internally forms the fal- 
ciform margin of the saphenous opening. 

The pubic portion, or pectineal fascia, is attached above to the ilio- 
pect, line, passes behind the femoral vessels, closely connected with the 
sheath, and merges into the iliac fascia and capsule of hip. 

The fascia lata has various deep processes : one is internal to the ten- 
sor vag. fern, on the surface, of the vastus ext. 

There are ext. and int. uttermuscular septa inserted into the linea 
aspera. 

The femoral vessels are surrounded by the funnel-shaped crural sheath, 
made of transversalis fascia in front and iliac fascia behind ; it is divided 
into three compartments — outermost for the artery, middle one for the 
vein, and innermost contains a lymphatic gland and fat, and when dis- 
tended by a femoral hernia is the crural canal, \ to If inches (14 to 34 
mm.) long. The crural ring (upper opening of the canal) is closed by 
the septum crurale. 

Describe the muscles of the hip. 

Internal Hip-muscles.— 1. M. Quadratics Liimhorum— A quadri- 
lateral muscle placed between the last rib and pelvis. Origin, ilio-lum- 
bar ligament, crest of ilium for 2 inches, from two, three, or four lumbar 
trans, processes by fleshy slips passing up anteriorly (Gray says this is a 
separate portion) ; insertion, inner half last rib and upper four lumbar 
trans, processes. 

Its sheath is formed behind by the costo-lumbar lig., and in front by part 
of the ilio-luinbar lig., middle and ant. layers of lumbar fascia. Henle de- 
scribes its origin as above and insertion below. If the twelfth rib is lacking, 
it goes to the eleventh. 

Nerves. — Last dorsal and upper lumbar. 

Actions. — Lateral flexor or both may extend spine. Draws down the last 
rib, giving fixed point for diaphragm, and aids inspiration (Quain); muscle 
of forced expiration (Henle). Fixed above, draws pelvis to one side, or both 
draw it forward. 

2. 31. Ilio-psoas. — It has a broad outer head, iliacus, and a narrow 
inner head, psoas magnus. 

Iliacus. — Origin, upper half of iliac fossa down as far as ant. inf. 
spine, posteriorly from ala of sacrum and sacro-iliac and ilio-lumbar liga- 



188 MUSCLES AND FASCIJE OF THE EXTREMITIES. 

merits. Inserted mostly into tendon of psoas ; outermost fibres pass to 
femur in front of and below small trochanter. 

Psoas Magnus [or Major). — Origin^ by five fleshy slips from anterior 
surfaces and lower borders of the lumbar trans, proc, and by a series of 
processes, each from a disk and contiguous mar-ins of two bodies: the 
highest is attached to the last dorsal and first lumbar, and lowest to 
fourth and lif'tli lumbar and intervert. subs, between them ; fibres also 
come from the sacro-iliac joint and sacrum. These attachments arc 
connected with arches passing over the middle of the vertebrae. The 
fibres all unite to a thick, long muscle running along the brim of the 
pelvis, passing under Poupart's, and inserted by a tendon into the small 
trochanter; separated by a bursa. 

The common tendon is also separated from the capsule of the hip by 
a bursa. 

31. iliac/is minor, or ilio-capsrdaris : Henle calls the third head. Origin, ant. 
inf. spine ; insertion, lower part of ant. intertrochanteric line or into the ilio- 
fem. ligament. 

3. 31. Psoas Parvus {or Minor). — Placed on the surface of psoas niag- 
nus ; from bodies of last dorsal and first lumbar vert, and disk between ; 
ends in a flat tendon merged into the iliac fascia and inserted into the 
ilio-pect. line and eminence. When present its origin is variable ; was 
absent on both sides in 40 per cent, of cases. 

External Hip-muscles. — First Layer. — 31. Gluteus Maximus. — 
A quadrilateral, very coarse muscle. Origin, posterior fourth of iliac 
crest and rough surface between it and posterior gluteal line, back of 
last two pieces of sacrum and first three of coccyx, great sacro-sciatic 
lig., and aponeurosis of erector spinse. 

The upper half and superficial fibres of lower half are inserted into 
fascia lata and continued into the ilio-tibial band; the deeper portion, of 
lower half into the gluteal ridge on the upper third of shaft of femur. 

Between this and great trochanter is a multilocular bursa and one or two 
small ones, another between it and vast. ext. : maybe another between it and 
tuber ischii. 

Varieties. — Agitator caudx, from coccyx to lower border of muscle. Fibres 
from sacro-sciatic lig. and sacrum are normally separated from the rest by 
areolar tissue, giving a bilaminar structure. 

Second Layer. — M. Gluteus Medius. — Origin, ilium between crest, 
post,, and middle curved lines, and from fascia covering it, and from a 
band attached to the ant. sup. spine ; fibres converge to an oblique im- 
pression going downward and forward on outer surface of the great tro- 
chanter: a small bursa between bone and tendon. There may be a sep- 
arate tendon to the upper part of the trochanter. 

Third Layer. — 1. M. Gluteus Minimus is covered by preceding, and 
rises from the whole surface on ilium between middle and inferior curved 
lines, and by a second head from the ant, sup. spine; fibres converge 
into an aponeurotic tendon on the outside of the muscle, inserted into 



THE HIP AND THIGH. ISO 

an impression on the front of the great trochanter. Tendon is bound 
down by band of capsule of joint from ilio-femoral lig. ; bursa between 
tendon and tubercle. 

May l>e divided into anterior and posterior parts. The anterior fibres, if 
separate, represent the scansorius of apes (ni. invertor femoris). 

l\ M. t)/riformis. — Origin, in pelvis by three digitations from second, 
third, and fourth pieces of sacrum, between and outside the ant. sacral 
foramina, from the hinder border of ilium below post. inf. spine, and 
from great sacro-sciatic lig. Emerges from pelvis by great sacro-sciatic 
foramen; inserted into upper border of great trochanter. 

May be divided by the ext. pop. nerve (high division of sciatic) ; inserted 
into 'capsule or absent. May be a bursa under its insertion. 

3. M. Obturator Interims. — Origin, deep surface of obturator mem- 
brane, except below; from the fibrous arch, completing the canal for 
the obturator vessels and nerve ; from hip-bone between thyroid foramen 
and sacro-iliac notch up to ilio-pect. line, and internally between foramen 
and subpubic arch ; from obturator fascia. Emerges by the small sacro- 
sciatic foramen, passes around the trochlear surface of ischium ; inserted 
with the gemelli into fore part of inner surface of great trochanter. It 
shows four or five tendinous bands on the surface turned toward bone, 
which receive pinnate fibres. A layer of cartilage covers the grooves on 
the ischium and a large synovial bursa. Another may be between the 
capsule and tendon. Henle describes the gemelli (gemini) as parts of 
this muscle, calling them its outer head. 

The gemellus sup., usually the smaller. Origin, outer and lower part 
of ischial spine. Gemellus inf. — Origin, upper part tuber ischii below 
obturator internus ; inserted with obturator int. into the great trochanter. 
They usually meet at origin beneath the obturator ; they overlap it at 
the insertion. The sup. gemellus may be absent or very small; inf. 
gemellus is more constant. 

4. M. Quadratus Femoris. — Origin, outer border tuber ischii ; inser- 
tion, horizontally outward into quadrate tubercle and back of femur to 
level of small trochanter. Bursa between it and small trochanter : it 
may be absent or replaced by the gemellus inf. 

Fourth Layer.— J/. Ohtureitor Externus. — Origin, inner half of 
outer surface of obturator membrane, body of pubis, rami of pubis and 
ischium ; passes out in a groove between acetabulum and tuber ischii, 
then up anil backward, close to lower and posterior surface of neck of 
femur to bottom of digital fossa. Sometimes bursa is between it and 
capsule. 

Nerves. — Ilio-psoas by second and third lumbar; those for iliacus are given 
off by ant. crural; glut. max. by inf. gluteal nerve; gluteus med. and min. 
by sup. gluteal nerve ; obturator int., gemelli, pyriformis, and quadratus fern, 
by sacral plexus ; obturator ext. by obturator nerve. 



190 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

Actions of glutei ou lower limb : 

Flexion. Extension. 

Glut, med., anterior fibres. Glut, maximus. 

" inin., " " " med., posterior fibres. 

" mill., '* " 

Adduction. Abduction. 

Glut, med., anterior fibres ) in sitting Glut, max., sligbt. 

" min., " " J posture. " nied., ) strong, whole muscle, es- 

" min., \ pecially mid. portion. 

Rotate in. Rotate out. 

Glut, med., anterior fibres. Glut. max. 

" min., " " " med., posterior fibres. 

" min., " " 

The gluteus maximus extends trunk on thigh as in ascending stairs; in walk- 
ing it is not used, as erect position is maintained by ligaments ; steadies and 
supports knee by ilio-tibial band. 

The iliopsoas flexes thigh and rotates out ; flexes body on thigh : the psoas 
bends the lumbar spine forward and laterally. 

Psoas parvus makes tense the iliac fascia. 

Piriformis, obturator int., and gemelli are external rotators after extension, 
abductors if thigh is flexed. 

Quadratus femoris is an external rotator, and may assist adduction. 

Obturator extemus is an external rotator; may flex and adduct. 

Describe the thigh-muscles. 

There are three sets— anterior, posterior, and internal, with superficial 
and deep layers, the former passing over two joints, the latter over one. 

Anterior Group. — First Layer. — 1. M. tensor vaginae femoris 
(tensor fasciae) lies in a groove between glut, med., rectus, and sartorius. 
Origin, anterior part of external lip of iliac crest, notch between the two 
spines, fascia over gluteus med. ; insertion, between two layers of fascia 
lata 3 or 4 inches below the great trochanter, and from the insertion 
fibres are prolonged into the ilio-tibial band ; the outer of the two lam- 
inae covers the muscle ; the deeper is connected with the origin of the 
rectus. 

2. 31. Sartorius (tailor muscle). — Origin, anterior sup. spine of ilium 
and small part of notch below; insertion, inner surface of tibia near 
tubercle, sending an expansion from upper border to capsule, one from 
lower border to fascia of leg, and one to tibia behind the tendons of 
gracilis and semitendinosus. It is oblique at first, then vertical to the 
knee, and then curves forward. 

Varieties. — Separate head from notch, ilio-pect. line, Poupart's, pubis close 
to symphysis; insertion into fascia lata, capsule of knee, or fascia of leg; an 
accessory insertion into fascia lata, femur, or lig. patellae; tendinous inscrip- 
tion on muscle. There is a common bursa beneath its tendon and those of 
the gracilis and semitendinosus. 

Second Layer. — M. Quadriceps Femoris, p. n. — Largest muscle of 



THE HIP AND THIGH. 191 

body, four parts closely united, (a) Rectus femoris, in a straight line 
from pelvis to patella. Origin^ by two beads: anterior one from ant. 
inf. spine, and posterior from impression just above acetabulum; they 

join at an angle of f>0° close below the acetabulum ; tendon is anterior 
above, then in centre of muscle. From tins are pinnate fibres ending 
in an inferior tendon covering the lower two-thirds of the posterior sur- 
face of the belly, and leaving a median cleft in the muscle. The lower 
tendon becomes free 3 inches above the patella; is attached to the upper 
margin of that bone, and helps form the common tendon. 

Some regard the "reflected head" as the main tendon, and the "straight 
head" as the secondary attachment. 

{b) The vastus externus (vastus lateralis, p. n.) is the outer part of the 
quadriceps. rig in, narrow from upper half of anterior intertrochan- 
teric line, outer part of root of great trochanter, outer side gluteal 
ridge, upper half linea aspera, its outer lip, from ext. intermusc. septum, 
and a strong aponeurosis extending over the upper two-thirds of muscle. 
It rises in a succession of layers, the upper overlapping the lower. 
Aponeurosis of insertion occupies the deep surface of muscle, joins the 
common tendon, and sends expansion to lat. patellar ligaments and rec- 
tus tendon. 

(c and d) Vastus interims (vastus medialis, p. n.) and crureus (femora- 
lis, p. n. ) seem to form one mass, but turn the rectus tendon well down, 
and above patella is an interval which can be followed up between the 
two tendons on line with lower end of anterior intertrochanteric line. 

The vastus interims rises from a superficial aponeurosis and deeper 
fibres from the spiral line, inner lip of linea aspera, and from tendons of 
adductor longus and magnus : they end in a deep aponeurosis which en- 
ters the common tendon. Its muscular fibres pass lower than those of 
the externus, and are inserted into the inner margin of the patella, some 
into the rectus tendon. 

Crureus, from upper two-thirds of anterior surface of femur, outer sur- 
face of femur in front of and below vastus ext., lower half of ext. inter- 
muscular septum ; fibres end in a superficial aponeurosis which forms 
the deepest portion of the common tendon. They rise from a series of 
transverse arches with intervening bare spaces on the front of the femur. 
Between this portion and the' vastus int. most of the internal surface of 
the bone is free. 

The common or suprapatellar tendon is inserted into the fore part of 
the upper border of the patella, and a few fibres are prolonged over its 
anterior surface into the lig. patellae. 

Third Layer. — M. subcruralis (articularis genu, p. n.) is the name of 
a few fibres which may be regarded as the deepest layer of the crureus. 
Origin, anterior surface of femur; insertion, separated by a fat layer 
from vasti into the synovial membrane of knee-joint. 

These muscles may be bilaminar. 



192 MUSCLES AND FASCIvE OF THE EXTREMITIES. 

Hunter's canal is a three-cornered passage in the middle two-fourths of the 
thigh, in the angle between the adductor magnus and longus and vastus inter- 
nus. It is made a canal by abridge of fascia, and contains the femoral artery, 
vein, and internal saphenous nerve. 

Nerves. Anterior crural for quadriceps and sartorius; superior gluteal for 
tensor vag. fern. 

Actions. — Sartorius Ilexes hip and knee with eversion of thigli ; rotates leg 
inward. 

Quadriceps femoris extends leg ; not necessary for maintenance of erect atti- 
tude. 

llcfhis fern, also flexes hip; its posterior head is tense when thigh is hent. 
Lower fibres of vastus int. draw patella in. 

Tensor vag. fern, rotates in and abducts, assisted by glut. max. ; -counteracts 
the glut, max., which tends to draw the ilio-tibial band backward. 

Posterior Group, or Hamstrings. — 1. M. Biceps Femoris. — 
Origin, long head by a tendon common to it and semitendinosus from 
inner impression on lower park of ischial tuberosity, and from sacro-sci- 
atic lig. ; short head from middle third of outer lip of linea aspera and 
ext, intermuscular septum ; fibres from both heads end in a tendon in- 
serted into the upper and outer part of head of fibula by two portions 
embracing the ext. lat. lig. ; some fibres pass forward and inward to the 
tuberosity of the tibia and to fascia of leg. 

A bursa is almost constantly between the tendon and ext. lat. lig., or an- 
other between the long head and semimembranosus. Short head absent; ad- 
ditional one from various sources. A slip from long head to gastrocnemius 
or to tendo Achillis. 

2. M. Semitendinosus. — From tuberosity of ischium and tendon com- 
mon to it and biceps for 3 inches. Terminates in lower third of thigh 
in a long, slender tendon, and curves forward in an expanded form into 
upper part of inner surface of tibia or ant. crest of tibia, and sends a 
process to fascia of leg. It is below the gracilis tendon, covered by the 
sartorius, and a bursa separates the three from the int. lat. lig. It has 
a thin, t oblique intersection in the middle of its belly. 

3. M. Semimembranosus. — Origin, tuber ischii above and outside the 
tendon of biceps and semitendinosus, and its tendon is grooved poste- 
riorly for the common tendon of those two muscles. Tendon of origin 
is on outer side of muscle for three-fourths the length of thigli ; ten- 
don of insertion, on opposite side of muscle, and turns forward and is 
inserted by four parts (1) into horizontal groove on back of inner tube- 
rosity of tibia ; (2) expansion is sent up and in as the posterior oblique 
lig. of the knee-joint; (3) down to the fascia over the popliteus muscle; 
(4) to form the short int. lat, lig. of the knee-joint. 

The hamstring muscles descend mostly in contact with each other and bound 
down by the fascia lata ; inferiorly they diverge the biceps to the outer side, 
semimembranosus and semitend. to the inner side, forming the upper borders 
of the popliteal space, the inferior margins of which are formed by the heads 
of the gastrocnemius. 

Varieties. — Great reduction in size of semimemb. or absence. 



THE BIP AND THIGH. 193 

If. ischio-aponcuroticus is a muscular slip from one or other hamstring to 
the fascia of the back of the leg. 

Nerves. — Great sciatic, from its int. popliteal division, except that to the 
short head of the biceps, which is from the ext. popliteal division. 

Actions. — Flex knee, and then can rotate tibia and drag it hack under 
femur; biceps outward, other two inward. Powerful extensors of hip, and 
limit flexion of (hat joint when knee is extended. 

Internal Group.— First Layer.— 1. M. Pectineus— Origin, ilio- 
pect line from ilio-pect. eminence and spine of pubis, and slightly from 
bone in front of this, and from fascia over the muscle ; insertion, femur 
behind small trochanter and upper part of line passing to the trochanter. 
At origin surfaces are frontal, at insertion are sagittal. 

2. M. Adductor Longus (add. fern, longus). — Flat and triangular, in- 
ternal to the pectineus, on same plane. Origin, short tendon from body 
of pubis below crest and near angle ; insertion, inner lip of linea aspera, 
united to vastus int. in front and adductor mag. behind. 

3. M. Gracilis, or adductor gracilis. — Origin, inner margin pubic bone 
and whole length of its inferior ramus, thin and flat, then narrow and 
thicker. A round tendon in lower third of thigh, curving forward be- 
low, inserted into inner side of tibia just above semitend. and covered by 
sartorius. 

Second Layer. — 31. Adductor Brevis. — Origin, body and inferior 
ramus of pubis below adductor longus, between gracilis and obturator 
ext. ; insertion, into the whole of the line from small trochanter to linea 
aspera behind the pectineus. It lies between the adductor mag. and 
longus. 

Third Layer. — 1. 31. Adductor Fern. Minimus. — This is what is de- 
scribed with the add. magnus, usually as its anterior and superior por- 
tion. Origin, body of pubis and ischio-pubic rami ; insertion, femur, in 
a line from quad. fern, to upper end of linea aspera, and a short distance 
along it. 

2. 31. Adductor Magnus. — Origin, ischial ramus internal to the above 
muscle and tuber ischii ; fibres pass in two layers, one to the inner lip 
of linea aspera, and other on inner side of opening for femoral vessels by 
a distinct rounded tendon to the adductor tubercle on the inner condyle 
of the femur. The femoral attachment is interrupted by three or four 
tendinous arches for the perforating arteries. 

Varieties. — Pectineus may be divided into two parts, supplied by different 
nerves, natural in many animals. May be inserted into capsule of hip. 

Add. longus may extend to knee, inseparable from add. magnus. 

Add. brevis may consist of two or three parts. 

Add. magnus, condylar part may be distinct ; usual in apes. 

Nerves. — Adductors by obturator nerve, but add. magnus also by great sci- 
atic ; pectineus regularly by a branch from ant. crural, an offset from the 
obturator and accessory obt. nerve, only occasionally present. 

Actions. — All adduct the thigh. Pectineus, add. longus, and brevis flex the 
hip, while part of the add. magnus from the ischial tuberosity to condyle 

13— A. 



194 MUSCLES AND FASCI2E OF THE EXTREMITIES. 

may extend the thigh and rotate in. Gracilis flexes knee and rotates- leg in- 
ward. Adductors and opponents, the gluteals, balance the body in walking. 

What are the internal rotators of the thigh ? 

(1) Anterior fibres of glut. nied. (2) and minimus; (3) tensor vaginae femo- 
ris ; and some say (4), the condylar part of the add. magnus. 

THE LEG. 
Describe the muscles and fasciae of the leg. 

Three groups as in the forearm, only the extensors are on the anterior 
side and flexors posterior. The number of muscles passing over two 
joints is less in the leg ; no muscle on the anterior and fibular side springs 
from above the knee. 

Fasciae. — The aponeurosis of the leg is not continued over the subcu- 
taneous surface of the bones, but intimately blended with the periosteum. 
It is dense at the upper and front part. Posteriorly it is continuous with 
fascia lata, and receives accessions from the biceps, sartorius, gracilis, 
and semitendinosus and membranosus tendons. Over the popliteal space 
are transverse fibres. It gives off intermuscular septa. In front of and 
on the sides of the ankle the apon. is strengthened by strong bands, 
forming the annular ligaments. 

The anterior annular ligament includes two structures — an upper band, 
lig. annulare, p. n., transversely between the anterior borders of the 
fibula and tibia. The tibialis anticus tendon alone has a synovial sheath 
under it. The lower band, lig. cruciatum, p. w,., resembles the letter Y 
placed on its side, one arm being external and two internal. The outer 
portion springs from the hollow of the os calcis, forming a strong loop, 
"fundiform ligament of Retzius" surrounding the peroneus tcrtius and 
extensor longus digit. The straight and most constant internal band 
passes to the internal malleolus over the extensor pollicis (hallicis), and 
practically beneath the tibialis ant. tendon ; the lower band crosses both 
those tendons, and becomes continuous with plantar fascia on the inner 
side of the sole. 

There are three synovial sheaths in all : a common one for the pero- 
neus tertius and extensor longus, one for the extens. poll. , and one for 
the tib. anticus ; may be a bursa between the fundiform lig. and neck 
of astragalus. 

Int. annular lig. {lig. laeiniattini, p. n.) covers the flexor tendons, 
completing canals ; it is attached to the inner malleolus and posteriorly 
to the inner side of the os calcis. 

The ext. ann. Ixg. [retinaculum peronceorum superius, ;>. n.) forms 
sheaths for the long and short peroneal tendons, passing from the outer 
malleolus to the os calcis. May be subcutaneous bursas over the mal- 
leoli and over the lower end of the tendo Achillis. 

Anterior Group. — 1. M. Tibialis Anticus ("chain muscle "). — Ori- 
gin, ext. tuberosity of tibia, upper half outer surface of that bone, and 
adjacent inteross. memb., fascia of leg, and intermusc. septum; insertion, 



THE LEG. 195 

oval mark on inner and lower part of int. cuneiform and first metatarsal, 
dividing into two slips. A small bursa may be under it near insertion. 

A part inserted into astragalus, a slip to head first metatarsal or first 
phalanx. 
M. tibio- fascialis anticus, from lower part of tibia to ann. lig. and deep fascia. 

2. M. Extensor Longus or Propria* HoMicis.* — Origin, middle two- 
fourths of narrow anterior surface of fibula and contiguous portion of in- 
terosseous membrane ; insertion, base of terminal phalanx of great toe. 
It spread^ in an expansion on each side over the metatarso-phal. articu- 
lation, and almost always sends a slip to base of first phalanx. 

Extensor ossis metatarsi hallicis is sometimes found as a slip from some sur- 
rounding muscle. 

M. extern, long, primi. internod. hall, is represented by tbe offshoot from the 
extensor proprius. 

3. M. Extensor Longus Digitorum Pedis. — Origin, ext. tuberosity 
of tibia, head and upper two-thirds of ant, surface of fibula, very largely 
from septa and fascia, Tendon divides into four slips for the four outer 
toes. They are continued into expansions which are joined on the first 
phalanx by processes from the interossei and lumbricales. They divide 
into three parts — the middle inserted into middle phalanx ; the lateral 
parts unite, and are inserted into the base of the terminal phalanx as in 
case of extensors of fingers. 

Tendons to second and fifth toes may be doubled; extra slips from one or 
more tendons to metatarsal bones, to short extensor, or to interossei ; a slip 
to great toe. Slip for little toe may be separable to origin. 

4. M. Peroneus Tertius. — Origin, below extensor longus dig., and 
united with it; lower third or more of ant. surface of fibula, from inter- 
oss. membrane, from septum between it and per. brevis; insertion, upper 
surface of base of fifth metatarsal, sometimes fourth. This muscle is 
peculiar to man. 

Nerves. — All by the ant. tibial nerve. 

Fibular Muscles. — 1. M. Peroneus Longus. — Origin, few fibres 
from outer tuberosity of tibia, head and upper two-thirds of ext, surface 
of fibula, fascia of leg, and septa on each side. It has an anterior and a 

{posterior head with muse. -cut, nerve between. Tendon begins in lower 
lalfof leg, passes behind ext, malleolus; then forward on outer side of 
os calcis, winds round tuberosity of cuboid, and enters its groove, crosses 
the sole obliquely, and is inserted into outer side of tuberosity of first 
metatarsal, and slightly into internal cuneiform : a frequent offset to 
base of second metatarsal and first dorsal interosseous. 

Both peroneal tendons are in the same sheath under the ann. lig., but on the 
os calcis each has its own sheath, separated by the peroneal spine, when it ex- 

* Allex or hallex, genitive hallicis, thumb or great toe — there is no word hal- 
lux to form the genitive hallucis. 



196 MUSCLES AND FASCIAE OF THE EXTREMITIES. 

iste, and a fibrous septum. A single synovial sac sends two processes down 
into the special sheaths. 

A second synovial membrane is in the cuboid groove. A sesamoid fibro-car- 
tilage or bone is .on the tendon, playing over the cuboid tuberosity. The 
special fascia binding down the peroneal tendons is the retinaculum peronx- 
orum infer ins, p. n. 

2. M. Peroneals Brevis. — Origin, lower two-thirds ext, surface of 
fibula, overlapping the peroneus long., from septa and a flat tendon 
on the surface turned toward the bone ; insertion, tuberosity at base of 
fifth metatarsal, sending a small slip to the outer edge of extensor of lit- 
tle toe or fore part of the metatarsal, bone. 

Varieties. — Fusion is rare. Slip from per. long, to base of third, fourth, or 
fifth metatarsal or to aclduct. hall. 

M. peroneus access, arises from fibula between brevis and longus, and joins the 
latter in sole of foot. 

M. peroneus quint, digiti, from lower fourth of fibula under per. brevis, in- 
serted into extensor apon. of little toe, commonly represented by slip of per. 
brevis. Occurs normally in many animals. 

M. peroneus quartus (13 percent.), from back of fibula between per. brevis 
and flexor hall., inserted into peroneal spine (peroneo-calcaneus) or tuberosity 
of cuboid (peroneo-cuboideus). 

Nerves. — Musculo-cut. branch of ext. popliteal nerve. 

Posterior Group.— Superficial Muscles— -1. Mm. Gastrocnemius 
and Soleus (m. triceps surae). — Gastrocnemius has two large heads from 
the femur, terminating in the middle of the leg in a common tendon. 
Outer head from depression on outer side ext. condyle above tuberosity, 
and from post, surface of femur just above that condyle. Inner head 
from upper part of int. condyle behind adductor tubercle, and lower end 
of supracondylar ridge. _ The two heads enlarge, and soon meet, do not 
join ; separated superficially by a groove and deeply by a thin band. 

The inf. tendon is broad and aponeurotic, and on the deep surface. 

The lower edge of each muscular part is convex downward : the inner 
head is the broader and thicker, and descends the lower. A bursa is ' 
between it and the semimembranosus, and another between it and the 
femur. 

Outer head may develop a sesamoid fibro- cartilage or bone over the 
condyle of the femur. 

Soleus. — Origin, externally from post, surf ice of head and upper third 
of shaft of fibula ; internally, oblique line and inner border of tibia to 
its middle, and from a tendinous arch over popliteal vessels and nerve ; 
fibres rise to a large extent from two tendinous laminae which descend 
in the muscle, one from the fibula and one from the tibia. Fibres from 
the ant, surfaces of these laminae converge to a median septum ; fibres 
from their post, surfaces pass down and back to an aponeurosis covering 
the back surface of the muscle. The tendon of insertion is prolonged 
from this aponeurosis, joined by the median septum. Muscular fibres 



THE LEG. 197 

are continued down on the deep surface of the tendo Achillis near to the 
heel. The tibial head is almost peculiar to num. 

Tendo Achillis, broad at first, contracts to within 1 •] inches of heel, 
then expands, and is inserted into middle of post, surface of tuberosity 
of os calris. with a bursa between, having all the characters of a syno- 
vial membrane, with vascular and fatty synovial tufts. 

2. M. Plantaris. — Origin, femur above external condyle and from 
post. lig. of knee-joint. Muscular belly 3 to 4 inches long, and the long-, 
slender tendon turns in between gastrocnemius and soleus to inner border 
of tendo Achillis, and inserted by its side into calcaneum. 

May join tendo Achillis, end in fascia of leg or int. aim. lig., or be enclosed 
in the tendo Achillis. Absent in 7.5 per cent. It is the remains of a super- 
ficial flexor of the digits, like the palmaris longus. 

3. M. Popliteus. — Origin, round tendon, 1 inch long, from groove on 
outer surface of ext. condyle of femur, within capsule of joint, in contact 
with semilunar cartilage, and by muscular fibres from lig. popl. arcuatum. 
Fibres pass down and are inserted into triangular surface of tibia above 
oblique line, and into aponeurosis over the muscle. The tendon is in the 
groove on the femur only in full flexion. Henle gives origin below and 
insertion above. 

M. popliteus minor (rare), from femur, inner side of plantaris, inserted into 
post. lig. of knee. 

M. peroneo-tibialis (1 in 7), from inner side of head of fibula to upper end of 
oblique line of tibia beneath popliteus ; constant in apes. 

Deep Muscles. — 1. M. Flexor Longus Digitorum Pedis (perforans). 
— Origin, inner portion post, surface tibia for middle two-fourths of length, 
from apon. over tibialis post. , from inner border of fibula. Descends be- 
hind int. malleolus, passes forward and obliquely outward, having crossed 
the tibialis post, tendon in the leg, and now crossing that of the flex, 
longus hall., in each case superficially. It divides into four parts for 
terminal phalanges of the four lesser toes. The whole arrangement with 
vinculae access, etc. is as for the fingers. 

M. flexor access, long, digitorum rises from fibula or tibia or deep fascia, and 
passes beneath int. aim. lig. and joins the long flexor or the accessorius. 

2. M. Tibialis Posticus, beneath the two long flexors. Origin, post, 
surface of inteross. membrane, outer part of posterior surface of tibia to 
middle of bone, whole inner surface of fibula, and from aponeurosis 
over it. Tendon along inner border of muscle, free at level of lower 
tibio-fib. articulation, passes behind inner malleolus ; inserted into tube- 
rosity of scaphoid, with offsets to the three cuneiform, to cuboid, bases 
of second, third, and fourth metatarsal, and to trans, tarsal lig. and abd. 
hall, tendon, and sends a thin process back to the sustentaculum tali. 

Varieties few. Tibialis secundus, or tensor of capside of ankle-joint, from lower 
half outer surface of tibia, below flex, digitorum, to capsule of ankle or ann. 
lig. between tibia and fibula. 



198 MUSCLES AND FASCIA OF THE EXTREMITIES. 

3. M. Flex. Longus Hall. — Origin, lower two-thirds post, surface 
fibula, septum between it and peronei; apon. common to it and flex, 
longus dig. Tendon at post, surface of muscle traverses groove on back 
of astragalus and under surface of sustentaculum, gives slip to flex. long, 
digitorum in sole of foot, and proceeds to the base of terminal phal. of 
great toe. 

Nearly always a slip from flexor hall, to flex digit., and (1 in 5) another 
from flex. dig. to flex. hall. 

Slip from flex. hall, passes to second and third toes, 52 per cent. ; to second 
only, 23 per cent. ; to second, third, and fourth, 19 per cent., or rarely to all 
four. 

M. peroneo-calcaneus interims (rare), from hack of fibula, passes over susten- 
taculum tali to os calcis. 

Nerves. — Gastrocnemius, plantaris, and popliteus by int. popliteal n. Soleus 
by int. popliteal and post, tibial. Flex. long, digit., flex. long, hallicis, and 
tibialis post, by post-tibial nerve. 

THE FOOT. 
Describe the muscles and fasciae of the foot. 

Fascia of dorsum is a thin layer oyer the extensor tendons, with deeper 
layers over the short extensors and interossei. 

Fascia of sole, (superficial) forms a thick cushion of fatty lobules bound 
down by bands passing vertically from skin to deep fascia. Small bursae 
over heel and first and fifth metacarpals. 

Deep Fascia of Sole. — Plantar fascia, central and two lateral portions. 
The inner is thin and loose, covers the abductor hall., and is continuous 
with dorsal fascia and int. ann. lig. Outer part covers abductor min. 
dig., and forms a thick band, especially between outer tubercle of os 
calcis and tuberosity of fifth metatarsal, continuous with dorsal fascia, 
and sends a prolongation forward over short flexors of little toe. 

Central portion has dense white, glistening fibres, from inner tubercle 
of os calcis to roots of toes ; divides into five processes in front. Thin 
trans, fibres cover the lumbricals and digital nerves. Identical arrange- 
ment as in palmar fascia: fibres to digital sheaths, superficial trans, lig., 
and skin, and deep processes to the trans, metatarsal lig. 

Two intermuscular septa are between the middle and lateral portions, 
giving partial origin to muscles. 

Superficial traits, lig. of toes is in folds of skin at interdigital clefts, 
connected to tendon-sheaths beneath. Connects all five digits. 

Muscles of Dorsum of Foot. 

1. M. Extensor Brecis Digitorum Pedis. — From fore part and upper 
and outer surface of os calcis, in front of groove for peroneus brevis 
tendon, and from ant. lig. of ankle. The tendon has several vertical 
leaflets from which muscular fibres rise, dividing into three bellies which 



THE FOOT. 19!) 

unite with the outer border of the long extens. for the second, third, and 
fourth toes. 

2. M. Extensor HaUicis Brevis (often described with the above). — 
Origin, two heads, miter from upper surface os calcis close by ant, edge, 
and connected with the extensor brevis digit. ; inner head from lowest 
arm oi' aim. lig. Tendon is free at tarso-metatarsal joint, passes under 
the tendon of the extensor long, hall., and is expanded and fastened to 
dorsum of first phalanx. 

Access, slips from different bones of tarsus to tendon for second toe, or one 
from cuboid to third. Number of tendons vary ; reduced to two, one doubled, 
or slip to little toe. A slip ending in a metatarso-pbal. articulation or dorsal 
inferos, muscle is rather common, especially between the great and second toe 
bellies. Deep slips, forming a transition to dorsal interossei, may occur ; may 
be a bursa over the second and third metatarsal bases. 

Muscles of the Sole. 

None corresponding to the pahnaris brevis : three groups as in the 
hand, middle group richer than that of hand. Great toe poorer than 
the thumb group. Little toe group, like number and arrangement. 

In the Middle.— 1. M. Flexor Brevis Digitorwm (perforatus).— 
Origin, inner tubercle of os calcis, plantar fascia, septa, and calc. cuboid 
lig. Terminates in four slender tendons inserted into sides of second 
phalanges of four outer toes; each divides and gives passage to the 
long flexor, as does the flex. subl. of the hand. 

Muscle may pass to all toes. The tendon to the little toe is always smaller 
than the others, and wanting in 23 per cent.; may be replaced (5 per cent.) 
by a small muscle from the long flexor or flexor access. ; origin of slip to fourth 
toe may be transferred to the long flexor. This is the rule for the outer toes 
of apes. 

2. Flexor Accessories (m. quadratus plantee, p. «.).— Henle calls it 
the "plantar head of the flexor long, digit." _ Flat quadrilateral muscle. 
Origin, two heads, internal and larger from inner surface of os calcis; 
external, narrow and tendinous, from outer surface os calcis and long 
plantar lig. ; insertion, ext. border and upper surface of flex. long, digit, 
tendon. 

Offsets can be traced to the second, third, and fourth toes, not always to the 
fifth. Muscle may end in flex. hall, tendon. May be absent. 

3. Mm. Lumbricales. — Four in number. Origin, at points of division 
of flex. long, digit, tendon, each attached to two tendons, except the 
most internal one ; they pass to inner side of four outer toes, inserted 
into bases of first phalanges (Henle). 

One or more absent ; doubling of third and fourth ; insertion into extensor 
tendons. Bursse between tendons and bases of first phalanges. 

Muscles of Great Toe-side.— ] . M. Abductor HaUicis. — Origin, 
inner tubercle os calcis, int. ann. lig., septum, plantar fascia; insertion, 



200 MUSCLES AND FASCIA OF THE EXTREMITIES. 

inner border of base first phalanx great toe, inner sesamoid boric, and 
tendon of extens. \or\g. hall. Slip to first phalanx second toe. May 
have a second head from scaphoid. 

2. M. Flexor Brevis Hallich. — Origin, flat process from cuboid inner 
border, from slip of tibialis post, tendon to the two outer cuneiform 
bones, from sheath flex. long, digit. ; inserted by two heads into inner 
and outer borders of base of first phalanx, in connection with abductor 
hall, and adductors. Sesamoid bone in each head. 

Origin from os calcis or long plantar lig. Sends slip to second toe, first plial. 
Inner head regarded by some as belonging to abductor. 

3. M. Adductor Hallicis has two heads as in hand, an oblique and 
transverse, only more separated. 

Caput Obliquum, p. n. — Origin, tarsal extremities of third and fourth 
metatarsals, sheath of peroneus long., calc.-cuboid lig., and third cunei- 
form ; insertion, outer side of base of first phal. of great toe, somewhat 
above the tendon of the peroneus long. 

Caput transversum, transversus pedis, is covered by flexor tendons. 
Origin, inf. tarso-metatarsal ligaments of three outer toes and trans, 
metatarsal lig. ; inserted with the oblique head and flexor brevis into 
first phalanx of great toe and extensor tendon. 

In the foetus the muscle is close to the oblique head at bases of metatarsals ; 
it subsequently travels forward along interosseous fascia. Opponens halt. 
into metatarsal of great toe is sometimes found. 

Muscles of Little Toe-side.— 1. M. Abductor Min. Dig — 
Origin, both tubercles of os calcis, ext. septum, band of plantar fascia 
between external tubercle and base of fifth metatarsal ; inserted into base 
fifth metatarsal and outer side base first phal. little toe. The tendon 
usually receives muscle-fibres from base fifth metatarsal. 

M. abductor oss. metatarsi quinti, 18 per cent, from ext. tubercle of os calcis 
to tuberosity of fifth metatarsal. 

2. 31. Flexor Brevis Min. Dig. — Origin, base of fifth metatarsal, and 
calc.-cuboid lig., sheath of peroneus long. ; insertion, base and ext. bor- 
der first phalanx little toe ; deeper fibres generally end on anterior half 
of fifth metatarsal. 

3. M. opponens min. dig. is occasionally (3.5 per cent.) separate from the 
flex, brevis min. dig., especially at its origin. It better be considered the 
inner belly of the flex, brevis, attached to the metatarsal bone. 

Mm. interossei, as in the hand, are seven in number, four dorsal and 
three plantar. The dorsal project downward as low as the plantar, and 
alternate with them. Only one muscle in the first space, two in the 
others. The second toe is their centre of insertion. 

Each dorsal interosseous has two heads and a central tendon, which is 
inserted partly into the base of the first phalanx and into extensor apo- 
neurosis. The first two are inserted, one on either side of the second toe, 



THE FOOT. 201 

the third and fourth into the outer sides of the third and fourth. Inner 
head of first is small, and rises from first metatarsal and int. cuneiform; 
the third and fourth receive fibres from sheath of peroneus long. 

Plantar interossei^ from inner and under surface of third, fourth, and 
fifth metatarsals, one-headed, and from sheath of peroneus long. In- 
serted to inner sides first phalanges of third, fourth, and fifth and ex- 
tensor tendons of toes. 

In the foetus the dorsal interossei are on the plantar aspect, and have a sin- 
gle origin, corresponding to the outer head of the fully-formed muscle. As 
the metatarsals hecome separated they pass more to the dorsum and acquire 
another head. 

Nerves. — Extensor brevis by ant. tibial. Flexor brcv. digit., abductor and 
flex, brew hall., and innermost lumbricalis by int. plantar; all the others by 
ext. plantar. 

Actions. — PopJiteus flexes knee and rotates leg in, pulls on capsule of joint, 
and keeps poplit. bursa open. The dorsum of the foot and ant. surface of leg 
is the extensor surface; the opposite side is the flexor surface, so that raising 
the foot on the front of the leg is really extension, and depressing it is flex- 
ion : it is customary to apply reverse terms to these acts. 

Gastrocnemius flexes knee, extends ankle, combines with soleus and lifts 
heel or raises body on toes. 

Tib. ant. and peroneus tert. flex ankle; the former rotates in, adducts, raises 
first metatarsal bone. 

Tib. jjost., peroneus long, and brevis are extensors. Tib. post, and flexors of 
toes rotate foot in. The three peronei and extensors of toes rotate out. 

Peroneus long, strengthens trans, arch, lifts outer border of foot in walking, 
extends foot, depresses first metatarsal, abducts fore foot, rotates out. 

Flexors and extensors of toes, interossei, and lumbricales act like the cor- 
responding muscles of the hand. 

Flex, accessorius modifies the action of the flex. long, dig., as those tendons 
cannot enter the foot in a straight line. 

The extensor brevis dig. does the same for the extensor communis, though 
here they are not so much needed, and their function is not so evident. 

Extensors of foot slightly rotate in ; flexors of foot slightly rotate out ; 
plant aris indirectly pulls up the capsule of ankle-joint and slightly aids the 
gastrocnemius. 

Flexors of Foot. Extensors of Foot. 

Tibialis anticus. Tendo Achillis. 

Extens. communis dig. Peroneus long, and brevis. 

Extens. propr. hall. Tibialis posticus. 

Peroneus tertius. Flex. long, digit, and hall. 

Adduction. Abduction. 

Tibialis post, (strongly). Peroneus brevis. 

Tendo Achillis (weakly). Peroneus longus. 

Perhaps tendons behind inner mall., 
perhaps tibialis anticus. 

Rotation in. Rotation out. 

Tibialis anticus (strongly). ■ Peroneus longus. 

Tendo Achillis. Extens. communis dig. 

Peroneus tertius. 



202 



MUSCI.ES AND FASdJE OF THE EXTREMITIES. 



The muscles of the foot, cspeciallj T of the little toe-side, are decreasing and 
the little toe becoming less important ; those of the hand are increasing, cor- 
responding to its complex movements over those of the foot. 

In comparing muscles of leg with forearm we notice (1) a reduction in ac- 
cordance with diminution of mobility; (2) disappearance of high origin of 
some superficial extensors; (3) development of tarsal attachment of super- 
ficial flexors of toes due to outgrowth of heel. 



MUSCULAR 
I. Muscles from Trunk 

Upper Limb. 
Trapezius, 
Cleido-mastoid, 
Rhomboidei, 
Lev. ang. scapulae, 
Serratus magnus, 

Deltoid, 

Teres minor. 
Latissimus dorsi, 
Teres major, 

Pectoralis major, 

Pectoralis minor. 
Subclavius. 

Supraspinatus. 
Infraspinatus, 

Subscapulars, 

Coraco-brachialis, 
Chondro-epitrochlearis, 



HOMOLOGIES. 

to Limbs or from Girdle to Humerus 
or Femur. 

Lower Limb. 



Ext. oblique and lumbar aponeurosis. 



Tensor vag. femoris. 

Gluteal fascia. 

Gluteus maximus, upper part. 

Gluteus maximus, larger part. 

Adductor longus. 
Adductor brevis. 



Psoas. 

Iliacus. 

Pectineus. 

Gluteus medius. 

Gluteus minimus. 

Pyriformis. 

Obturator internus with Gemelli. 

Obturator externus. 

Quadratus femoris. 

Adductor magnus. 

Gracilis. 



II. Muscles of Arm and Thigh. 



Biceps, 



Humeral head of biceps, 
Brachialis anticus, 
Dovso-epitrochlearis, 
Triceps : 

a. Scapular head. 

b. Humeral heads. 
Anconeus. 



Ischial head of biceps fem. 

Semitendinosus. 

Semimembranosus. 

Femoral head of biceps fem. 

Sartorius. 
Quadriceps : 

a. Rectus femoris. 

b. Vasti and crureus. 



MUSCULAR HOMOLOGIES. 



203 



III. Muscles of Forearm and Leg-. 



Pronator teres, 
Flexor carpi radialis, 
Flexor carpi ulnaris, 
Palmaris longus, 
Flexor sublimis digitorum, 
Flexor longus pollicis, 
Flexor profundus digit., 

Lnmbricales, 

Pronator quadratus. 

Ulno-carpeus, 

Radio-carpeus, 

Supinator longus. 

Extensor carpi radialis longior. 

Extensor carpi radialis brevior. 

Extensor communis digit., 

Extensor minimi digiti, 

Extensor carpi ulnaris, 

Supinator brevis. 
Extensor ossis metacarpi poll., 
Extensor longus poll., 
Extensor brevis poll., 

Extensor indicis, 

Extensor medii digiti, 
Extensor brevis digitorum, 



Popliteus. 
Gastrocnemius. 

Plantaris. 

Soleus and flexor brevis digit. 
Flexor longus hallicis. 
Flexor longus digit. 
Flexor accessorius. 
Lumbricales. 

Per oneo- calcaneus interims. 
Tibialis posticus. 



Extensor longus digit. 
Peroneus tertius (?). 
Peroneus longus. 
Peroneus brevis. 

Tibialis anticus. 
Extensor longus ball. 
First slip of extensor brevis digitorum. 
Second slip of extensor brevis digi 
torum. 

Extensor brevis digit. 



IV. Muscles of Hand and Foot. 



Palmaris brevis. 
Abductor pollicis, 
Flexor brevis pollicis, 
Opponens pollicis, 
Adductor obliquus pollicis, 
Adductor transversus pollicis, 
Abductor minimi digiti, 
Flexor brevis minimi digiti. 
Opponens minimi digiti. 

a. Superficial part. 

b. Deep part, 

First palmar interosseous. 

Second palmar interosseous, 
Otber interossei correspond. 



Abductor ballicis. 
Flexor brevis ballicis. 
Opponens hallicis. 
Adductor obliquus ballicis. 
Adductor transversus ballicis. 
Abductor minimi digiti. 



Flexor brevis min. dig. 
Opponens min. dig. 

First plantar interosseous. 
Second plantar interosseous. 



204 THE HEART. 



ANGEIOLOGY. 

THE HEART. 
Describe the pericardium. 

The pericardium is a fibro-serous membrane which invests the heart 
and the great vessels at their origin for about 2 inches. Below it is 
attached to the diaphragm and its central tendon ; in front it is sep- 
arated from the sternum by the thymic remains, some areolar tissue, and 
overlapped by the margins of the lungs, especially of the left ; behind it 
are the oesophagus, bronchi, and descending aorta ; laterally it is cov- 
ered by the pleura3, with the phrenic nerve and vessels running between 
the two membranes. 

The pericardium consists of a fibrous and a serous layer. The fibrous 
layer forms a tubular investment for the great vessels which is lost on 
the external coat, and can be traced afterward into the deep cervical 
fascia. It is attached below to the diaphragm and its central tendon. 
The vessels invested are the aorta, superior vena cava, both pulmonary 
arteries, and all the pulmonary veins. 

The serous layer invests the heart and is reflected on to the fibrous 
layer. It also invests the great vessels for about 2 inches. The aorta 
and pulmonary artery are completely invested, the pulmonary veins and 
both the vense cavae only partially. 

Describe the heart. 

The heart is a hollow muscular organ, of a somewhat conical form, 
lying between the lungs and enclosed by the pericardium. It contains 
four chambers, an auricle and a ventricle on each side. 

Give its general position and measurements. 

It lies obliquely, the base being directed upward, backward, and toward 
the right, and extending from the level of the fifth to that of the eighth 
dorsal vertebra, and # the apex looking downward, forward, and to the 
left, its impulse against the chest-wall being felt in the fifth left inter- 
space, about 3]- inches from the middle of the sternum. The heart lies 
more in the left than in the right side of the chest, its base being held 
in position by the great vessels which are connected with it ; its posterior 
surface is flat, formed chiefly by the left ventricle, and rests on the dia- 
phragm ; and its anterior surface, formed chiefly by the right ventricle, 
but also partly by the left, is convex and covered to some extent by the 
lungs. Of the borders, the right is long and thin, and the left is 
shorter and thick. The length of the heart is 5 inches ; its greatest 
breadth is 3? inches; its thickness is about 2} inches. Its weight 
is 10 to 12 ounces in the male, 8 to 10 in the female, and it increases 
with age. 



THE HEART. 205 

How is the heart subdivided externally? 

Externally it presents a deep transverse groove, the auriculo- ventricu- 
lar, which marks oft' an upper or auricular and a lower or ventricular 
portion : this latter part presents a longitudinal furrow on the front and 
back, the former being somewhat to the left, the latter to the right. 

How is the heart subdivided internally ? 

The interior of the heart is divided by a longitudinal septum into a 
right and left part, and these, in turn, are divided into an auricle and a 
ventricle. 

Describe the right auricle. 

The right auricle is larger than the left, its wall being about 1 line 
in thickness and its capacity two ounces. Its cavity is divided into two 
parts, the sinus venosus and the appendix auriculae, the former lying 
between the entrances of the two venae cava3, the latter overlapping the 
commencement of the aorta. _ Within the auricle the following parts 
present themselves for examination : 

(1) The orifice of the superior vena cava, looking downward and 
forward. 

(2) The orifice of the inferior vena cava, at the lowest part, near the 
septum, looking upward and inward. 

(3) Between the two caval openings a projection, the tuberculum 
Loweri. 

(4) The opening of the coronary sinus, between the inferior cava and 
the auriculo-ventricular opening, and protected by the fold of endocar- 
dium forming the coronary valve. 

(5) Numerous small openings (foramina Thebesii) of the venae cordis 
minimae. 

(6) The auriculo-ventricular opening. 

(7) The Eustachian valve, between the front of the vena cava and 
the above-mentioned orifice. It is semilunar in form, the free concave 
margin sending one cornu to join the front of the annulus ovalis and the 
other to the auricular wall. 

(8) The fossa ovalis, at the back of the septum, in the situation of the 
fcetal foramen ovale, its prominent margin being known as the annulus 
ovalis. 

(9) The musculi pectinati, small elevated columns which traverse the 
appendix and the adjacent part of the sinus. 

Describe the right ventricle. 

The right ventricle is triangular, and extends nearly to the apex of the 
heart. It is bounded internally by the convex surface of the septum 
ventriculorum, and prolonged above and internally into a pouch, the in- 
fundibulum, or conus arteriosus, from which springs the pulmonary 
artery. Its cavity has a capacity of three ounces. On opening the 
ventricle the following parts are presented for examination : 



206 THE HEART. 

(1) The auriculo-ventricular orifice, oval in form and placed near the 
right side of the heart. Around its circumference is a fibrous ring, and 
it is guarded by the tricuspid valve. 

(2) The opening of the pulmonary artery, circular in form, at the 
summit of the conus arteriosus, near the septum ; is guarded by the pul- 
monary valve (semilunar). 

(3) The tricuspid valve consists of three triangular flaps formed of 
fibrous tissue covered by endocardium. They are continuous with one 
another at their bases, and their free margins and ventricular surfaces 
give attachment to the chordae tendineae. Their central part is thick 
and strong, the lateral margins thinner and flexible. 

(4) The chordae tendineae are attached as follows : several to the at- 
tached margin of each flap, blending with the fibrous ring ; several to 
the strong central part ; and the finest and most numerous to the mar- 
gins of each curtain. 

(5) The columnae carneae are projecting bundles of muscular substance 
found all over the ventricular wall excepting the conus arteriosus. They 
are of three classes : the first are mere ridges, attached by one side and 
both extremities ; the second are attached only by both extremities ; 
the third (musculi papillares) are attached by only one extremity, the 
free end having chordae tendineae attached to it. 

(6) The three semilunar valves guard the pulmonary orifice. They 
are semicircular, their free margins being thick and tendinous and pre- 
senting at the middle a small fibrous nodule, the corpus Arantii. On 
each side of this body, just behind the free margin, the valve presents a 
small thinned-out interval, and when the valves are closed during dias- 
tole these intervals Qunulce) are in contact, and so also are the three 
nodules. These latter prevent any leakage from the triangular space 
which would otherwise be left. At the commencement of the pulmo- 
nary artery are three pouches, the sinuses of Valsalva, placed one be- 
hind each valve. They resemble those of the aorta, but are smaller. 

Describe the left auricle. 

It is smaller and thicker-walled than the right, and consists, like the 
right, of a sinus and an appendix. The latter overlaps the pulmonary 
artery. Within it presents the following features of interest : 

The orifices of the pulmonary veins, opening two into the right and 
two into the left side ; the auriculo-ventricular orifice ; and a few mus- 
culi pectination the inner side of the appendix. 

Describe the left ventricle. 

It is longer than the right, and enters into the formation of the apex. 
[ts walls are three times as thick as those of the right. Within it pre- 
sents for examination — 

The auriculo-ventricular orifice, which is smaller than the right and 
guarded by the mitral or bicuspid valve; and the aortic opening, in front 
and to the right of the preceding, guarded by the semilunar valves. 



STRUCTURE OF THE HEART. 207 

The mitral valve is attached, like the tricuspid on the right side. It 
consists of two curtains which are larger and thicker than those of the 
tricuspid, and of two smaller segments, one at each angle of junction of 
the former. They are furnished with chordae tendinesc. 

The aortic semilunar valves are similar to but larger and stronger than 
the pulmonary valves. 

Columnse carneae are found as in the right ventricle, and the musculi 
papillares consist of two groups and are very large. 

The inner surface of the heart is lined by a thin membrane, the endo- 
cardium, continuous with the inner lining of the great blood-vessels, and 
helping to form by its folds the various valves. 

The heart is supplied with blood by the coronary arteries, and with 
nerves by the cardiac plexuses, formed by branches of the pneumogas- 
tric and sympathetic nerves. 

STRUCTURE OF THE HEART. 
What are the two structures of which the heart is made up ? 

Fibrous rings and muscular fibres : the former serve as points of at- 
tachment of the latter. 

What is the situation of the fibrous rings ? 

They surround the auriculo-ventricular and arterial orifices, and give 
attachment to the valves of the heart and great vessels, in addition to 
the muscular attachment. 

How may the muscular fibres be divided? 

1 . Into those of the auricles ; 2. those of the ventricles. 

Describe the arrangement of the fibres of the auricles. 

These are in two layers, a superficial and a deep. The former layer is 
common to both auricles ; the latter is peculiar to each. The superficial 
layer passes across from one auricle to the other anteriorly, and back 
again posteriorly, thus enclosing them in a kind of ring. The deep layer 
is made up of looped and annular fibres. The looped fibres arch over 
the auricle ; the annular fibres encircle each auricle. 

Describe the arrangement of the fibres of the ventricles. 

There are seven layers in each ventricle : in the left ventricle the fibres 
of the first or most external layer are continuous with the fibres of the 
seventh or most internal layer ; those of the second with the sixth, those 
of the third with the fifth, while the fourth layer runs horizontally and 
continuously around the ventricle. The direction of the other layers is 
as follows : first layer, from above downward and from left to right ; 
seventh layer, just the opposite ; second layer, like the first, but more 
obliquely ; sixth layer, just the reverse ; -while the third and fifth layers 
are nearly horizontal. The union of the first and seventh layers is at 
the apex of the heart, and forms the vortex or whorl In the right 



208 SYSTEMIC ARTERIES. 

ventricle, arrangement exactly the same, except union of first and seventh 
layers, which takes place all along the anterior coronary groove. All 
the fibres are much more delicate than those of the left ventricle. 



ARTERIES. 

Describe the pulmonary artery. 

It is a short, wide vessel, 2 inches in length. Commencing at the 
base of the right ventricle, it curves upward and backward, to end 
under the transverse aorta by dividing into a right and a left branch. 
Relations : in front, second left intercostal space and cartilage, left bor- 
der of sternum ; behind, origin of aorta, left auricle ; above, transverse 
aorta, remains of ductus arteriosus; to the right, right appendix and 
coronary artery, ascending aorta ; to the left, left appendix and coronary 
artery. 

This vessel, with the ascending aorta, is enclosed in a sheath of peri- 
cardium. It winds around the aorta, being at first in front, and later to 
the left side, of the ascending portion. In fcetal life the ductus arteri- 
osus connects it a little to the left of its bifurcation with the transverse 
aorta. 

Each branch enters the root of the corresponding lung ; the right, the 
larger, passing behind the ascending aorta and superior vena cava ; the 
left, in front of the descending aorta. The left divides into two branches 
for the lobes of the left lung ; the right also divides into two primary 
branches for the upper and lower lobes. From the lower one of these is 
sent a branch to the middle lobe. 



SYSTEMIC ARTERIES. 
Describe the aorta. 

The aorta is the main trunk from which spring the systemic arteries. 
From the base of the left ventricle it runs upward, forward, and to the 
right as far as the second right cartilage ; then backward and to the left, 
over root of left lung, to the fourth dorsal vertebra ; thence.^ along the 
spine, it descends through the thorax and abdomen to divide, at the 
fourth lumbar, into the common iliacs. 

It has been divided, for convenience of description, into the arch and 
the descending aorta. The arch is subdivided into the ascending, trans- 
verse, and descending parts ; the descending aorta, into the thoracic and 
abdominal portions. 

ARCH OF THE AORTA AND ITS BRANCHES. 
Describe the ascending part of the arch. 

It runs upward, forward, and to the right, from a point opposite the 
lower border of the third left cartilage, to the upper border of the second 



ETC. 209 

right cartilage. Close to its origin it presents three small dilatations, the 
sinuses of Valsalva, indicating the situation of the semilunar valves, and 
along the right side a bulging, the sinus magnus. Relations: in front, 
pulmonary artery, right appendix, thoracic fascia, right pleura, pericar- 
dium, remains of the thymus gland ; behind, root of right lung, including 
right pulmonary vessels, left auricle; to the right, right auricle, supe- 
rior vena cava ; to the left, pulmonary artery. 

Describe the transverse part of the arch. 

This part passes backward and to the left as far as the left side of 
body of the fourth dorsal vertebra. Eolations: in front, lungs and 
pleura, thymic remains, left vagus, phrenic and superficial cardiac 
nerves, left superior intercostal vein ; behind, trachea, oesophagus, tho- 
racic duct, deep cardiac plexus, left recurrent nerve ; above, left innom- 
inate vein and the branches of this portion of the aorta — viz. innom- 
inate, left carotid, and subclavian arteries ; below, left bronchus, 
bifurcation of pulmonary artery, ductus arteriosus, left recurrent nerve. 

Describe the descending part of the arch. 

It descends to lower border of fifth dorsal vertebra, ending in the 
thoracic aorta. Relations : in front, root of left lung covered by pleura ; 
behind, left side of body of fifth dorsal vertebra; right side, oesophagus, 
thoracic duct ; left side, left lung, covered by pleura. 

Name and describe the branches of the arch of the aorta. 

They are five : coronaiy, right and left, from the ascending part ; and 
the innominate, left carotid, and left subclavian, from the transverse 
part. The descending part gives off no branches. 

The coronary arteries supply the heart and the coats of the great ves- 
sels. They emerge on either side of the pulmonary artery, between it 
and the corresponding appendix auriculae. Each arises from a sinus of 
Valsalva, just above the free margin of the corresponding semilunar 
valve, and is distributed to the muscular substance of the heart, its 
valves and septa, running along the grooves on its surfaces, and anasto- 
mosing freely with the other, and, by means of twigs to the aorta and 
pulmonary artery, with the pericardiac and bronchial vessels. Each 
divides into two primary branches, the right vessels running in the pos- 
terior and the left in the anterior grooves. 

ARTERIES OF THE HEAD, NECK, AND UPPER 
EXTREMITY. 

Describe the innominate artery (brachio-cephalic). 

This is the largest branch. It arises in front of the left carotid, and 
runs obliquely to the right sterno-clavicular joint, where it divides into 
the right common carotid and right subclavian. Relations : in front, 
manubrium sterni, sterno-hyoid and thyroid muscles, thymic remains, 
left innominate and right inferior thyroid veins, inferior cervical cardiac 
14— A. 



210 SYSTEMIC ARTERIES. 

nerve from right vagus ; behind, trachea and pleura ; right side, pleura, 
right vagus, right phrenic nerve, and the right innominate vein ; left 
side, remains of the thymus and trachea. The left carotid artery is 
behind and to the left of this vessel. The innominate regularly gives 
off no branches. Occasionally, however, a thymic or bronchial branch 
or the arteria thyroidea ima arises from it, 

Describe the common carotid arteries. 

They are identical in course, branches, and relations in the neck, but 
differ in their origin. Thus, the right is a branch of bifurcation of the 
innominate, while the left is a primary branch of the transverse aorta. 
From its origin the left carotid passes obliquely upward and outward to 
the left sterno-clavicular joint, and from that point follows a course cor- 
responding to that of the right carotid. We describe, therefore, a tho- 
racic portion of the left carotid artery. Its relations are as follows : in 
front, sternum, sterno-hyoid and thyroid, thymic remains, left innom- 
inate vein ; behind, trachea, oesophagus, thoracic duct ; left side, left 
subclavian artery, left vagus ; right side, innominate artery, which is also 
somewhat in front, 

In the neck each carotid ascends from the sterno-clavicular joint to the 
level of the upper border of the thyroid cartilage, there dividing into 
the external and internal carotids. Each is enclosed, with the internal 
jugular vein and vagus, in a sheath of deep cervical fascia, the several 
structures being partitioned from one another within the sheath. The 
artery is internal, the vein external, the nerve between them, but on a 
posterior plane. Relations: in front, integument, fasciae, platysnia, 
sterno-mastoid, hyoid, thyroid, and omo-hyoid muscles, descendens and 
communicantes noni nerves, sterno-mastoid artery, superior, middle thy- 
roid, and anterior jugular veins, and a branch connecting anterior jugular 
with facial; behind, longus colli, rectus anticus major, spinal column, 
inferior thyroid artery, sympathetic and recurrent laryngeal nerves ; 
outer side, internal jugular vein, vagus; inner side, trachea, oesophagus. 
larynx, pharynx, tigroid gland, inferior thyroid artery, and recurrent 
nerve. In the lower part of the neck the internal jugular diverges from 
the artery on the right side, but approaches, and may cross it, on the 
left, The common carotid regularly gives off no branches, but a verte- 
bral, thyroid, or laryngeal branch may arise from it on either side. 

Describe the external carotid artery. 

This vessel runs from the bifurcation of the common carotid to the 
neck of the lower jaw, and there divides into the superficial temporal 
and internal maxillary. _ At its origin it is anterior and internal to the 
internal carotid, and at its termination is imbedded in the parotid gland. 
Relations: in front, integument and fascia), sterno-mastoid. digastric, and 
stylohyoid muscles, part of parotid, facial and hypoglossal nerves, lin- 
gual, facial, and temporo-maxillary veins ; behind, styloid process; witli 
its remaining muscles, part of parotid gland, and the glosso-pharyngeal 



ETC. 211 

nerve ; internally, pharynx, hyoid bone, part of parotid, separating it 
from the lower jaw and stylo-maxillary ligament, and the superior laryn- 
geal nerve. 

Name and describe the branches of the external carotid. 

Besides branches given off directly to the muscles in its course and to 
the parotid gland, they are the following: Anterior branches, superior 
thyroid, lingual, facial; posterior branches, occipital, posterior auricular ; 
internal branch, ascending pharyngeal; terminal branches, superficial 
temporal and internal maxillary. 

I. The superior thyroid runs beneath the omo-hyoid and sterno- 
hyoid and thyroid muscles to the gland, uniting with its fellow and with 
the inferior thyroid. It supplies the gland, the muscles in its course, 
and the following-named branches: 

[a) Hyoid, to lower border of bone, joins its fellow. 

(b) Superficial descending or sterno-mastoid crosses common carotid 
to the sterno-mastoid muscle. 

(e) Superior laryngeal, beneath thyro-hyoid, pierces membrane to in- 
terior of larynx. 

id) The erico-thyroid runs across that membrane and joins its fellow. 

II. The lingual ascends to the great cornu of the hyoid bone, runs 
forward parallel with it, ascends to the tongue, and runs along its under 
surface to the tip. It is at first superficial, lying on middle constrictor ; 
later covered by digastric and stylo-hyoid, resting on the same muscle. 
It then ascends between the hyoglossus and genioglossus ; finally, as the 
ranine artery, it runs on the lingualis to tip of tongue, along with the 
gustatory nerve, covered only by mucous membrane. The first part is 
crossed by the hypoglossal nerve. The second part is in the. triangle 
formed by the diverging bellies of the digastric below and the hypo- 
glossal nerve above. The artery lies above the central tendon of the 
digastric, below the nerve, and beneath the hyoglossus. Branches: 

(a) Hyoid, to upper border of hyoid bone, joins its fellow. 

(b) Dorsalis Ungues, from beneath the hyoglossus, joins its fellow, and 
supplies the tonsil, epiglottis, and soft palate, besides the tongue. 

(c) Sublingual runs on genio-glossus to the gland. Branches supply the 
mylo-hyoid and gums, and a twig joins its fellow across the middle line. 

III. The facial runs under the lower jaw upon mylo-hyoid, and 
grooves the upper and back^ part of the submaxillary gland. It then 
crosses the jaw at the anterior border of the masseter, runs over the 
cheek by the angle of the mouth, and alongside of the nose to the inner 
canthus of the eye, ending in the angular artery, which anastomoses 
with the nasal branch of the ophthalmic. Its course is very tortuous. 

This vessel lies at first beneath the digastric and stylo-hyoid, but is 
covered only by the platysma where it crosses the jaw. In the face it 
lies on the buccinator, levator anguli oris, and levator labii superioris, 
covered by the platysma, risorius, and z} 7 gomatici. The vein is external 
and at some distance from the artery, and pursues a straight course. 



212 SYSTEMIC ARTERIES. 

Branches of the facial nerve cross, and the infraorbital nerve is under, 
the artery. 

Its bronchi* arc the following : a cervical group, including the inferior 
palatine, tonsillar, submaxillary, submental; and & facial group: the in- 
ferior labial, coronary upper and lower, lateralis nasi, and the angular. 

(a) The inferior or ascending palatine runs at first between the stylo- 
glossus and pharyngeus; then between the internal pterygoid and phar- 
ynx. It crosses the superior constrictor to the soft palate, joins its fel- 
low, and supplies the tonsil, Eustachian tube, palate, and the muscles 
along its course. 

{b) The tonsillar pierces superior constrictor to tonsil and tongue. 

(c) The submaxillary includes several glandular branches. 

(d) The submental, the largest branch, runs beneath the jaw, sending 
twigs through the mylo-hyoid to join the sublingual. It turns over the 
symphysis, giving offsets to the chin and lower lip, and joins its fellow 
and the inferior dental. It supplies also the muscles along its course. 

(e) Muscular branches are derived from the vessel at every point, both 
in the face and neck. 

(/) The inferior labial, beneath the depressor anguli oris, joins mental, 
submental, and inferior coronary.^ 

(g) The coronary arteries ramify between the orbicularis oris and the 
mucous membrane, the inferior joining its fellow and the inferior labial ; 
the superior, arising frOm behind the zygomaticus major, gives off the 
artery of the septum, besides other nasal branches. 

(h) Lateralis nasi, to side of nose. 

(i) Angular is the terminal branch. 

IV. The occipital artery is at first covered by the digastric and 
stylo-hyoid muscles and crossed by the hypoglossal nerve. It then 
crosses the internal carotid sheath and spinal accessory nerve to the in- 
terval between the atlas and mastoid process, hying here in the occipital 
groove, and then pierces the origin of the trapezius to ramify in the 
scalp as high as the vertex. Branches : 

{a) Muscular, all along its course. 

(b) The sterno-mastoid branch enters the muscle with the spinal ac- 
cessory nerve. 

(c) The mastoid branch, through the mastoid foramen. 

{d) Princeps cervicis divides into a superficial branch, lying under the 
splenius, and sending twigs through it to anastomose with the super- 
ficial cervical ; and a deep branch beneath the complexus, to join branches 
of the vertebral and profunda cervicis. 

(e) A meningeal branch enters the jugular foramen. 

V. The posterior auricular artery, resting on the styloid pro- 
cess, passes beneath the parotid to the groove between mastoid and 
auricle, and divides into two branches, the auricular and mastoid, the 
latter supplying the scalp. This artery crosses the spinal accessory and 
is crossed by the facial nerve. Besides branches to the various muscles 
and the parotid, it gives off the following : 



ETC. 213 

(a) The siylo-mastoidj through the foramen, to the mastoid cells and 
tympanum. In the young subject a branch joins the tympanic from the 
interna] maxillary artery to form a circle, from which twigs pass to the 

tympanic membrane. Another branch, in the aqueductus I allopii, joins 
the petrosal artery of the middle meningeal. 

(/;) The auricular, anastomosing with branches of the temporal. 

VI. The ascending pharyngeal ascends between pharynx and in- 
ternal carotid to the base of the skull, giving oft' branches which may be 
divided into three sets — viz. (1) three or four phm-yngeal, to the con- 
strictors, the lower joining branches .of the superior thyroid, and the 
largest to the superior constrictor, supplying also the palate and tonsil. 
(2) Several meningeal branches entering the foramen lacerum me- 
dium, jugular and anterior condylar foramina. (3) The prevertebral 
branches, to the muscles and glands in its course and to the vagus and 
sympathetic nerves, anastomosing with the ascending cervical. 

The external carotid divides into the superficial temporal and in- 
ternal maxillary while imbedded in the parotid gland, the former being 
the smaller. 

VII. The superficial temporal ascends to about 2 inches above 
the zygoma, and divides into the anterior and posterior temporal. The 
former supplies the muscles, pericranium, and skin over the forehead, 
joining the supraorbital and frontal ; the latter runs upward and back- 
ward over the side of the head, anastomosing with its fellow, the occip- 
ital, and posterior auricular. The temporal supplies the articulation of 
the jaw, the parotid, and the muscles in its course, and gives off the 
following-named branches : 

(a.) The transverse facial, lying at first between Stenson's duct and the 
zygoma upon the masseter, and accompanied by branches of the facial 
nerve. It joins branches of facial and infraorbital. 

{b) Middle temporal, to the muscle, after perforating temporal fascia, 
grooves the squamous portion, and supplies an orbital branch. It anas- 
tomoses with the deep temporal. 

(c) The anterior auricular, two or three, join branches of the posterior 
auricular after supplying fore part of pinna. 

VIII. The internal maxillary is described in three portions — viz. 
maxillary, pterygoid, and spheno-maxillary. The first portion runs be- 
tween the jaw and internal lateral ligament. The second runs forward 
and upward upon the external pterygoid. The third enters the spheno- 
maxillary fossa between the two roots of the external pterygoid. 

Branches: from the first or maxillary portion the tympanic, middle 
and small meningeal, inferior dental ; from the second or pterygoid part 
the deep temporal, pterygoid, masseteric, buccal ; from the third or sphe- 
no-maxillary part the alveolar, infraorbital, superior or descending pala- 
tine, Vidian, pterygopalatine, spheno-palatine. 

(a) The tympanic, through the Glaserian fissure, joins the stylo-mas- 
toid and the tympanic arteries, and supplies a deep auricidar branch. 
(See Stylo-mastoid Artery.) 



214 SYSTEMIC ARTERIES. 

(b) The middle meningeal ascends between the roots of the auriculo- 
temporal nerve, through the foramen spinosum, and divides on entering 
the cranium into an anterior and a posterior branch. These ramify on 
the inner surface of the calvaria as far as the frontal and occipital 
bones, uniting with the posterior and anterior meningeal. Branches 
pass to the Gasserian ganglion and dura mater ; through the sphenoidal 
fissure to the orbit; and through the hiatus FaJlopii a petrosal branch 
passes to join a branch of the stylo-mastoid artery. 

(c) The small meningeal enters the foramen ovale, sometimes arising 
from the preceding. 

(d) The inferior dental traverses the dental canal, escaping at the 
mental foramen. It sends forward an incisor branch in the bone, gives 
off to the groove a mylo-hyoid branch, and unites with its fellow and 
with the submental and labial arteries. It supplies the teeth by small 
twigs to the roots from below. 

(e) The two deep temporal, anterior and posterior, join other temporal 
branches. The anterior sends twigs through the malar bone to unite 
with the lachrymal. 

(/) The pterygoid branches supply the muscles of that name. 

(g) The masseteric crosses the sigmoid notch to the deep surface of the 
muscle. 
'(h) The buccal, on the buccinator, joins branches of the facial. 

(i) The alveolar sends branches through the posterior dental canals to 
the molar and bicuspid teeth, the antrum, and gums. 

(j) The infraorbital arises with the preceding, traverses the canal, 
supplying the orbital muscular branches and an anterior dental, and, es- 
caping at the infraorbital foramen, supplies the lachrymal sac, sending 
branches also over the face. It joins branches of the facial and oph- 
thalmic arteries. 

(/»•) The descending (or superior) palatine enters the posterior palatine 
canal, and runs along the hard palate to the anterior palatine foramen, — 
thence through Stenson's foramen to join the naso-palatine artery. It 
sends branches through the accessory palatine canals to the soft palate. 

(/) The Vidian, through its canal to the pharynx and Eustachian 
tube, and gives a branch to the tjmipanum. 

(m) The ptery go-palatine, through its canal to the sphenoidal sinus 
and pharynx. 

(n) The nasal, or sphenopalatine, through that foramen to the spongy 
bones, ethmoidal cells, and antrum. One large branch, the artery of the 
septum or naso-palatine, unites with the termination of the descending 
palatine artery. 

Describe the internal carotid artery. 

This is a very tortuous vessel, and at its origin is farther from the 
median line than the external carotid, deriving the name ''internal" 
from its distribution. For description it is divided into four parts : The 
first, or cervical, extends from the bifurcation of the common carotid to 



ARTERIES OF THE HEAD, ETC. 215 

the carotid canal; the second, or petrous, is in the carotid canal ; the 
third, or cavernous, runs in the cavernous sinus; and the fourth, or cere- 
bral, is the terminal portion. 

Cervical portion^ relations: in front, skin and fasciae, sterno-mastoid, 
digastric, and the styloid process with its muscles; external carotid artery 
and its occipital and posterior auricular branches; hypoglossal, glosso- 
pharyngeal nerves, and pharyngeal branch of vagus; behind, rectus 
capitis anticus major, sympathetic and superior laryngeal nerves; exter- 
nally, internal jugular vein and vagus, lboth being in the same sheath 
with the artery, but having each a separate investment, the nerve being 
posterior to, and between, the artery and vein. Near the base of the 
skull the spinal accessory, glossopharyngeal, the vagus, and hypoglossal 
nerves emerge between the vein and artery. Internally, pharynx and 
tonsil, ascending pharyngeal artery, superior and external laryngeal 
nerves. 

The petrous portion is at first in front of the tympanum and internal 
car, and then runs forward and inward to the inner side of the fora- 
men lacerum medium, and ascends, accompanied by the sjmipathetic, to 
the cavernous sinus. 

The cavernous portion lies on the floor of the sinus, surrounded by the 
sympathetic, the sixth nerve being external. 

The cerebral portion pierces the dura mater internal to the anterior 
clinoid process, lying at the inner extremity of the Sylvian fissure, be- 
tween the second and third nerves. 

Name and describe the branches of the internal carotid. 

The first portion gives off no branches. The second sends a tympanic 
branch through a foramen in the carotid canal. The third gives off the 
artericB receptaculi to the pituitary gland, Gasserian ganglion, the cav- 
ernous and inferior petrosal sinuses. One of these branches is the ante- 
rior meningeal. It also gives off the ophthalmic. 

The ophthalmic artery passes through the optic foramen, below and 
external to the nerve, then crosses the latter, and runs beneath the supe- 
rior oblique muscle to the inner angle of the eye, and divides into the 
frontal and nasal. It gives off two sets of branches — viz. orbital and 
ocular. The orbital are the following: 

(a) The lachrymal runs above the external rectus to the gland, send- 
ing several malar branches through the bone to the temporal fossa and 
cheek, a branch back through the sphenoidal fissure to join the middle 
meningeal, and several to the conjunctiva and upper lid to join other 
palpebral vessels. 

(b) The supraorbital, through the notch, joining the temporal and 
facial branches. 

(c) The ethmoidal branches, posterior and anterior, run through the 
ethmoidal canals to the ethmoidal cells. The former supplies also the 
roof of the nose ; the latter runs with the nasal nerve, and divides into 
a meningeal and a nasal branch. 



216 SYSTEMIC ARTERIES. 

{d) The palpebral branches, superior and inferior, form arches on the 
lids between the orbicularis muscle and tarsal cartilages, the inferior 
sending a branch to the nasal duct. They anastomose with the orbital 
branch of the temporal and with the infraorbital artery. 

(e) The frontal, at inner angle of the orbit, unites with the supra- 
orbital. 

(/) The nasal crosses the tendo-oculi to lachrymal sac, and gives off 
the dorsalis nasi branch. It joins the angular artery. 

{g) The muscular branches supply the muscles of the eyeball. They 
are superior and inferior, and belong to the ocular group. The other 
ocular branches are — 

(/*) The arteria centralis retina 3 , within the optic nerve to retina. 

(/) The ciliary pierce the sclerotic to supply the iris, ciliary body, and 
choroid. They are derived from the ophthalmic directly or from some 
of its branches, and are divided into the anterior set, six to eight in 
number ; the short, ten to fifteen ; and the long, two in number. 

The fourth portion of the internal carotid supplies the following 
branches : 

(a) The anterior cerebral, along the front part of the great longitu- 
dinal fissure, and is joined, by the anterior communicating, with its fellow. 
The two vessels then, side by side, curve around the front of the corpus 
callosum and run back over its upper surface, breaking up into terminal 
branches which supply the anterior cerebral lobes, anterior locus per- 
foratus, and the optic nerves. 

{b) The middle cerebral, along the Sylvian fissure to the island of 
Reil, supplying the pia mater over the anterior and middle lobes, as well 
as the anterior perforated space. 

(c) The posterior communicating, running back to join the posterior 
cerebral. 

(</) The anterior choroid, to descending horn of lateral ventricle, send- 
ing branches to the choroid plexus, velum, and hippocampus major. 

Describe the subclavian arteries. 

Each vessel is divided into three parts, the first running to the inner 
margin of the scalenus anticus ; the second, behind that muscle ; the 
third, from its outer border to the lower border of the first rib, where it 
becomes the axillary artery. The right and left vessels differ only in 
their first portions, the right arising behind the sterno-elavicular joint, 
from the innominate ; the left, from the aorta as a primary branch. 

First Portion of the Right Subclavian. — Relations: in front, the 
sterno-mastoid, hyoid, and thyroid muscles ; deep cervical fascia ; inter- 
nal jugular, vertebral, and right innominate veins ; and superficially, the 
anterior jugular vein, some loops of the sympathetic nerve and its car- 
diac branches, the vagus and phrenic nerves; behind, the transverse 
process of the seventh cervical or first dorsal vertebra, longus colli, re- 
current laryngeal, and sympathetic nerve and pleura ; below, the pleura 
and recurrent nerve. 



ETC. 217 

First Portion of the Left Subclavian. — Relations: in front, the left 

hum- and pleura, left carotid artery; internal jugular, vertebral, and left 
innominate veins; vagus, phrenic, and cardiac nerves; and superficially, 
the sterno-thyroid, hyoid, and mastoid muscles: behind, sympathetic 
nerve, oesophagus, and thoracic duct, the longus colli separating it from 
the spine; externally, pleura; internally, trachea, oesophagus, and tho- 
racic duct. 

Second Portion of the Subclavian. — Relations : in front, the scalenus 
anticus, phrenic nerve, and the vein; behind and below, pleura. 

Third Portion. — Relations: in front, the clavicle, subclavius, cervical 
fascia, suprascapular artery, external jugular, suprascapular and trans- 
verse cervical veins, supraclavicular nerves from cervical plexus, and 
the nerve to the subclavius ; behind, the scalenus medius ; above, omo- 
hyoid, brachial plexus ; below, first rib. 

Name and describe the branches of the subclavian. 

They are the vertebral, thyroid axis, internal mammary, and superior 
intercostal. They are all derived from the first portion on the left side ; 
on the right the superior intercostal arises from the second portion. 

I. The vertebral enters the transverse foramen of the sixth cervical 
vertebra, ascends through those of the other cervical vertebrae, and, 
grooving the upper border of the atlas from without, backward, and in- 
ward, pierces the dura mater. It then ascends'to the front of the 
medulla through the foramen magnum, uniting at the lower border of 
the pons with its fellow to form the basilar. The thoracic duct crosses 
the left arter} 7 . It is at first behind the internal jugular and its own 
vein ; then between the scalenus anticus and longus colli. In the for- 
amina it is accompanied by a S3 T m pathetic plexus, it is in front of the 
spinal nerves, and it crosses the suboccipital nerve on the atlas. 

Branches: the cervical branches are muscular, to the deep cervical 
region, joining the occipital and deep cervical ; and the lateral spinal, 
entering the intervertebral foramina. 

The cranial branches include — 

(a) The postenor meningeal, to the falx cerebelli and cerebellar fossae. 

(b) The anterior spinal, along the front of the medulla, joins its fellow 
to form the upper part of the anterior median artery of the cord. This 
is a small vessel which runs in the anterior median fissure of the cord, 
beneath the pia mater, as far as the cauda equina. It is formed below 
by offsets entering the intervertebral foramina, and dividing into ascend- 
ing and descending branches. It is thus really a series of short vessels 
connected together. These branches are contributed by the vertebral 
and ascending cervical, intercostal, lumbar, ilio-lumbar, and lateral sacral 
from above downward. 

(c) The posterior spinal descends along the posterior nerve-roots to the 
cauda equina. It is formed in a similar manner to the anterior, but it is 
bilateral. 

(cl) The posterior inferior cerebellar divides under the cerebellum into 



218 SYSTEMIC ARTERIES. 

two branches. The inner runs to the notch between the hemispheres ; 
the outer, to their under surface and the choroid plexus of the fourth 
ventricle, joining the superior cerebellar. 

The basilar, formed by the two vertebrals, runs to the upper border 
of the pons, and divides into the two posterior cerebrals. It gives off 
the following branches: 

(a) Several transverse arteries on each side. One, the auditory, enters 
the internal meatus; another, the anterior inferior cerebellar^ to the ante- 
rior border of the cerebellum. 

(b) The superior cerebellar, to upper surface, joining the inferior cere- 
bellar. 

(c) The posterior cerebrals, to under surface of the posterior lobes, 
receiving the posterior communicating. They give off the posterior 
choroid branches and supply the posterior perforated space. 

The circle of Willis is an important anastomosis, formed in front by 
the anterior cerebrals, which are connected by the short anterior com- 
municating artery, which is only two lines in length, and behind by the 
two posterior cerebrals, united to the internal carotid, close to the origin 
of the anterior cerebrals, b} 7 the posterior communicating branches. In- 
cluded in this circle are the lamina cinerea, the tuber cinereum, the in- 
fundibulum, the corpora albicantia, the optic commissure, and the pos- 
terior perforated space. 

II. The thyroid £xis, from the fore part of the subclavian, divides 
close to its origin into the inferior thyroid, suprascapular, and transverse 
cervical. 

(1) The inferior thyroid, to the gland behind the sympathetic and the 
common carotid, joins its fellow and the superior thyroid, giving off the 
following branches : 

[a] Laryngeal, runs with recurrent nerve ; {b) tracheal, joining bron- 
chial arteries; (c) oesophageal; (d) muscular, to the inferior constrictor 
and hyoid depressor muscles and the scaleni ; and (e) the ascending cer- 
vical. 

The last-named runs between the scalenus anticus and the rectus 
anticus major, joining the vertebral and giving other branches which, 
with the lateral spinal of the vertebral, help form the anterior median 
artery of the cord. 

(2) The suprascapular runs at first between the scalenus anticus and 
the sterno-mastoid, crosses the subclavian, and runs behind the clavicle 
to cross the transverse ligament of the scapula. In the supraspinous 
fossa it runs beneath the muscle, which it supplies, and terminates in 
the infraspinatus where it joins the dorsal and posterior scapular artery. 
A supra-acromial branch joins the acromio-tnoraeic artery ; a branch 
supplies the shoulder-joint, and another the subscapular fossa. 

(3) The transverse cervical divides at the anterior border of the trape- 
zius into a superficial cervical branch, ascending beneath and supplying 
that muscle, and a posterior scapular running along the posterior border 
of the scapula to join the subscapular artery at its inferior angle. 



ETC. 219 

III. The internal mammary descends from the under surface of 
the subclavian along the hinder surface of the costal cartilages, ■> inch 
from the sternum, as far as the sixth interspace, and divides into the 
musculophrenic and superior epigastric. At first, behind the subclavian 
vein and the phrenic nerve, it lies against the pleura, but separated from 
it below by the triangularis sterni. 

• Branches: (a) Comes nervi phreniei, to the diaphragm along with the 
nerve, joins the phrenic arteries. , 

(b) Mediastinal, to the glands in the anterior mediastinum, thymus 
gland, and areolar tissue. 

(c) Pericardiac, to upper part of the pericardium. 

(d) Sternal to the bone and triangularis sterni. 

The four preceding, with the bronchial and intercostal arteries, con- 
tribute branches which unite to form the subpleural mediastinal plexus. 

(e) Anterior intercostal, to the six upper spaces, joining the aortic 
branches. 

(/) Anterior or perforating branches, through the spaces, and sup- 
plying the mammary gland and pectoral muscles. 

(g) Musculo-phrenic pierces diaphragm at eighth rib and runs behind 
the cartilages to the last interspace, giving off the lower intercostal 
branches. 

{h) Superior epigastric pierces sheath of the rectus, sends a branch 
to join its fellow, and finally joins the deep epigastric. 

IV. The superior intercostal crosses in front of the neck of the 
first rib, and supplies the first and part of the second interspace. 

Its profunda cervicis branch passes backward between the seventh 
cervical vertebra and the first rib, ascends under the complexus to the 
axis, and joins the princeps cervicis and vertebral arteries. 

Describe the axillary artery. 

The continuation of the subclavian is called the axillary artery. It 
extends from the lower border of the first rib to the lower border of the 
teres major tendon, and there becomes the brachial. It is described in 
three parts : the first, above the pectoralis minor ; the second, behind it ; 
and the third, below it. 

First Portion. — Relations: in front, pectoralis major, subclavius, costo- 
coracoid membrane, acromio-thoracic and cephalic veins, external anterior 
thoracic nerve ; behind, first intercostal muscle, first digitation of serratus 
magnus, posterior thoracic nerve; externally, brachial plexus; internally, 
axillary vein. 

Second Part. — In front, pectoralis major and minor ; behind, subscap- 
ulars ; internally, vein. 

The posterior cord of the plexus is behind it, the outer cord outside, 
and the inner cord to its inner side. The plexus thus surrounds the sec- 
ond portion of the artery. 

Third Part. — In front, integument, fasciae, pectoralis major, median 
nerve, its inner head, internal cutaneous nerve ; behind, subscapularis, 



220 SYSTEMIC ARTERIES. 

tendons of latissimus dorsi and teres major, nmscnlo-spiral and circum- 
flex nerves ; externally, coraco-brachialis, musculo-cutaneous, and me- 
dian nerves; internally, tlie vein, brachial venae comites, ulnar and 
lesser internal cutaneous nerves. 

Branches: first part, superior and acromial thoracic; second part, 
long and alar thoracic ; third part, subscapular and circumflex, poste- 
rior and anterior. 

{(>) The superior thoracic, between pectorales to side of chest, joins 
the intercostals. 

(b) The acromial thoracic divides into an acromial branch, to join the 
suprascapular; a thoracic, uniting with other thoracic branches; and a 
descending, along with the cephalic vein, between pectoralis and deltoid. 

(c) The long thoracic, to pectorales, serratus, and mamma, joining the 
intercostal arteries. 

(d) The alar thoracic, to axillary glands. 

(e) The subscapular, along the lower border of the subscapulars, join- 
ing branches with the intercostal and posterior scapular arteries. Its 
dorsalis scapulas branch passes through a triangle formed by the two 
teretes and the triceps, and divides into three sets — viz. dorsal, to the 
infraspinous fossa; ventral, to the subscapular fossa; and descending, 
to run between the teretes muscles. 

(/) The circumflex arteries encircle the neck of the humerus. The pos- 
terior, with the nerve and veins, passes through the quadrangular space 
formed by the triceps, teretes, and humerus, and ends in the deltoid and 
shoulder-joint. It joins the superior profunda and acromial arteries. 
The anterior, beneath the biceps and coraco-brachialis, to end under the 
deltoid, sends a twig to the shoulder-joint along the bicipital groove. 

Describe the brachial artery. 

The brachial artery extends from the end of the axillary, at the lower 
border of teres major, to £ an inch below the elbow-joint, dividing into 
the radial and ulnar arteries. Relations: in front, integument and Fascia, 
bicipital fascia, median basilic vein, and median nerve ; behind, triceps, 
coraco-brachialis, brachialis anticus, musculo-spiral nerve, and superior 
profunda artery; externally, coraco-brachialis, biceps, median nerve; 
internally, basilic vein, venae comites, internal cutaneous, ulnar, and 
median nerves. 

Name and describe the branches of the brachial artery. 

(a) The superior profunda, along the musculo-spiral groove, sends a 
branch to the shoulder-joint, anastomosing with the circumflex; the 
posterior articular artery, to the back of the elbow, joining the interosse- 
ous recurrent ; branches to muscles ; and, finally, the continuation of the 
vessel joins the radial recurrent in front of the outer condyle. 

(/>) The nutrient artery] to the humerus, enters the foramen. 

(c) The inferior profunda, on the inner head of the triceps, accom- 
panies the ulnar nerve, and divides into a branch to the front of the inner 



ARTERIES OF THE HEAD, ETC. 221 

condyle and another to the back of it. The former joins the anterior, 
and the latter the posterior ulnar recurrent artery. 

(<!) The muscular branches, to the coraco-brachialis, biceps, and 
brachialis anticus. 

{(■) The anastomotica magna runs on the brachialis anticus inward to 
form an arch with the posterior articular under the triceps. This artery 
Forms anastomoses with all the vessels around elbow, excepting only the 
radial recurrent. 

The brachial divides, about £ an inch below the elbow, into the radial 
and ulnar arteries. 

Describe the radial artery. 

It runs from the bifurcation of the brachial along the radial side of 
the forearm to the wrist, and winds back to its posterior surface. It 
then enters the palm through the first dorsal interosseous, and runs 
across the hand to form the deep palmar arch by joining the deep 
branch of the ulnar. 

In the forearm, relations: in front, integument, fascia, and supinator 
longus; behind, from above downward, it lies on the tendon of the biceps, 
supinator brevis, pronator teres, flexor sublimis, flexor longus pollicis, ' 
pronator quadrants, and radius ; on ulnar side, flexor carpi radialis and 
pronator teres ; on radial side, supinator longus and radial nerve, its 
middle third. 

In the wrist it lies on the external lateral ligament, scaphoid, and 
trapezium, and is covered by the extensors of the thumb, cutaneous 
veins, and by filaments of the radial and musculocutaneous nerves. 

In the hand it lies on the metacarpal bones and interossei, covered 
by the flexor tendons, opponens, flexor brevis minimi digiti, and flexor 
brevis pollicis. 

Name and describe the branches of the radial artery. 

In the forearm : (a) The radial recurrent, between the supinator longus 
and the brachialis anticus, joins superior profunda, 
(6) The muscular, to the radial side of the forearm. 

(c) The svperficialis voice, through the muscles of the thumb ; some- 
times it ends in them, or it may be very large, or may complete the 
superficial arch. 

(d) The anterior carped runs inward to join in the anterior carpal arch 
with the ulnar branch. 

In the wrist : (e) The posterior carped joins the ulnar branch, forming 
the posterior carpal arch. This arch gives off the third and fourth dor- 
sal interosseous branches. 

(/) The metacarpal runs on the second dorsal interosseous muscle, 
and joins, by branches, the first sup. perforating and palmar digital 
arteries. It divides into two dorsal digital branches for the index and 
middle fingers, their adjacent sides, and it also gives off an inferior per- 
forating artery to the corresponding palmar digital. 



222 SYSTEMIC ARTERIES. 

{;/) Two dorsales pollicis, along the sides of the thumb. 

[h) The dorsalis indicis, along the radial side of the index finger. 

In the hand: (/) The princeps polli'ds, along the ulnar side of the 
first metacarpal to the first phalanx, where it divides into two branches 
for the palmar sides of the phalanges. 

(j) The radialis indicts, along radial border, palmar surface of index 
finger. 

(k) The superior perforating arteries pass back between the heads of 
the last three dorsal interossei muscles to join the dorsal interosseous 
arteries. 

(/) Three or four palmar interosseous branches join the palmar digital 
arteries at the finger-clefts. 

Describe the ulnar artery. 

The ulnar artery runs along the inner side of the forearm to the wrist, 
crosses the annular ligament and the palm of the hand, and joins the 
superficialis voice to form the superficial arch. 

In the forearm, relations: in front, integument, fascia, and superficial 
flexor muscles, median nerve, and palmar cutaneous branch of the ulnar 
nerve ; behind, brachialis anticus, flexor profundus digitorum ; ulnar side, 
flexor carpi ulnaris, median nerve above and ulnar nerve below ; radial 
side, flexor sublimis. 

At the wrist the nerve is internal to the artery, and the pisiform bone 
is internal to the nerve. 

In the hand, as the superficial arch, it is covered by the skin, pal- 
maris brevis, and palmar fascia. It rests on the annular ligament, super- 
ficial flexor tendons, and divisions of the median and ulnar nerves. 

Name and describe the branches of the ulnar artery. 

Forearm : (a) The anterior ulnar recurrent, to front of inner condyle, 
joins the anastomotica magna and inferior profunda. 

(b) The posterior ulnar recurrent, beneath flexor sublimis to back of 
inner condyle, and between the heads of the flexor carpi ulnaris along 
the ulnar nerve ; joins the posterior interosseous recurrent and inferior 
profunda arteries. 

(c) The interosseous, to the upper border of the interosseous mem- 
brane, where it divides into the anterior and posterior interosseous arte- 
ries. The first runs on the front of the membrane, which it pierces 
above the pronator quadratus. to join the posterior branch and the 
posterior carpal arch. It supplies the median artery to the nerve, mus- 
cular branches, and the nutrient vessels of the radius and ulna. A 
branch joins the anterior carpal arch. The posterior interosseous de- 
scends along the back of the forearm, between the superficial and deep 
muscles, and joins the anterior. It gives off" the interosseous recurrent, 
which ascends beneath the anconeus to join, behind the olecranon, in the 
anastomosis at the elbow-joint, 

{(J) The muscular, to the ulnar side of the forearm. 



THE ABDOMINAL AORTA AND ITS BRANCHES. 223 

(r)Tlie anterior and posterior carpal join similar branches of the radial 
to form the carpal arches, the posterior giving a metacarpal branch to 
the little tinner, ulnar side. 

(/) The d<rp branch joins the radial to form the deep palmar arch. 

(//) The digital, four, to little, ring, middle, and ulnar side of index 
finger. 

THE THORACIC AORTA AND ITS BRANCHES. 
Describe the thoracic aorta. 

The thoracic aorta descends from the lower border of the fifth to the front 
of the last dorsal vertebra. Relations : in front, root of left lung, peri- 
cardium, and oesophagus ; behind, azygos minor vein and spinal column ; 
to left, left lung and pleura, and, below, oesophagus; to right, oesophagus 
above, vena azygos major, thoracic duct. 

Name and describe the branches of the thoracic aorta, 
fa) The pericardiac, to the pericardium. 

(b) The bronchial, to the bronchial glands and the oesophagus; they 
are also the nutrient vessels of the lung. The right one arises from the 
front of the aorta together with the left upper. The left consist of an 
upper and lower branch. The bronchial vessels run along back of the 
corresponding bronchus and divide with the bronchi, entering the sub- 
stance of the lung. The right sometimes arises from the first aortic 
intercostal. 

(c) Four or five oesophageal, joining the inferior thyroid above, the 
gastric and phrenic below. 

(d) The posterior mediastinal, to glands and areolar tissue. 

(e) The intercostal. These are nine or ten, the superior intercostal 
from the subclavian supplying the upper space or two. They run under 
the pleura and sympathetic, the right behind the oesophagus and thoracic 
duct. They cross obliquely to the edge of the rib above, running at first 
on the external, and then between the two sets of intercostal muscles. 

Each divides into two branches running along the contiguous borders 
of the two ribs, and each uniting anteriorly with the corresponding branch 
of the anterior intercostals from the internal mammary. The first joins 
the superior intercostal; the last two, the lumbar and epigastric. In 
general, each lies between the vein above and the nerve below. 

A posterior branch runs from each, and divides into a spinal branch 
to the cord and a muscular branch. 

THE ABDOMINAL, AORTA AND ITS BRANCHES. 
Describe the abdominal aorta. 

It runs from the last dorsal to the left side of the middle of the body 
of the fourth lumbar vertebra, there dividing into the two common iliacs. 
Relations: in front, lesser omentum, stomach, pancreas, transverse duo- 
denum, left renal and splenic veins, peritoneum forming mesentery, 



224 SYSTEMIC ARTERIES. 

aortic and solar plexuses; behind, receptaculum chyli, thoracic duct, left 
lumbar veins, and spine ; to the right, crus of diaphragm, vena cava, 
great azygos vein, thoracic duct, right semilunar ganglion, splanchnic 
nerve ; to left, splanchnic nerve, left semilunar ganglion. 

Name and describe its branches. 

The parietal are — I. The phrenic, a right and a left. Their origin 
is inconstant, from the aorta separately or in common, or from one of its 
branches. They run across the crura to the under surface of the dia- 
phragm, and each passes outward, behind the vena cava on the right, 
the oesophagus on the left side, and divides into an internal branch, join- 
ing its fellow and the other phrenics^ and an external, joining the inter- 
costal arteries. Each supplies suprarenal capsular branches, the right 
sending branches to the liver and vena cava ; the left, to the spleen and 
oesophagus. 

II. The lumbar, five on each side, pass behind the psoas and sym- 
pathetic, and divide into a dorsal branch to the back, also sending twigs 
to the spinal anterior median artery (see Anterior Spinal Branch of Ver- 
tebral), and an abdominal branch running between the abdominal mus- 
cles, joining branches of epigastric, intercostal, ilio-lumbar, and internal 
mammary. 

III. The middle sacral, along the middle of the front of the sacrum 
to the coccyx, joining the lateral sacral and entering Luschka's gland. 

The visceral branches : IV. The cceliac axis, i inch long, divides 
into the gastric, hepatic, and splenic. It is covered by the lesser omen- 
tum, rests below on the pancreas; on each side is a semilunar ganglion, 
and on the right the lobus Spigelii, on the left the stomach. 

{a) The gastric artery runs to the cardiac orifice, thence to the right, 
along lesser curvature, in the lesser omentum as far as the pylorus. It 
supplies both surfaces of the stomach and the oesophagus, anastomosing 
with the splenic, hepatic, and oesophageal arteries. 

{b) The hepatic artery passes below the foramen of Winslow to the 
pylorus, then ascends in the lesser omentum, anterior to that foramen, 
to the transverse fissure of the liver, and divides into a right and a left 
branch. Its pyloric branch passes along the lesser curvature to meet the 
gastric. Its cystic branch from the right division ascends on neck of 
the gall-bladder and supplies it by two branches. The other branch of 
the hepatic, the gastro-auodenalis, divides behind the lower part of the 
duodenum into a superior pancreatico-duodenal branch, descending be- 
tween the pancreas and duodenum to join the inferior artery of the 
same name; and the gastro-epiploica aextra, passing in the omentum 
toward the left, along the great curvature, to meet the sinistra. 

(c) The splenic runs tortuously to the left, along the upper border of 
the pancreas, and divides near the spleen into branches which enter at 
the hilus, some passing to the stomach. 

Branches : Pancreatic, numerous, small ; and one larger, the pancre- 
atica magna, accompanies the duct of Wirsung. 



THE ABDOMINAL AORTA AND ITS BRANCHES. 225 

Five to seven vasa brevia^ in the gastro-splenic omentum, to great end 
of stomach, joining the gastric and gastroepiploic vessels. 

The gastro-epiploica sinistra runs to the right, along the great curva- 
ture, to join the dextra. 

V. The superior mesenteric supplies the small intestine except 
the first part of the duodenum, as well as the caecum, and ascending 
and transverse colon. Emerging from between the transverse duodenum 
and pancreas, it crosses the former, and descends in the mesentery to 
the right iliac fossa with its vein and a plexus of nerves. It ends by 
anastomosing with its own ileo-colic branch. 

Branches: (a) The inferior pancreatico-duodenal, joining the superior 
from the hepatic artery. 

(b) Twelve to fifteen vasa intestini tenuis to jejunum and ileum, run- 
ning parallel within the mesentery, each vessel bifurcating. These di- 
visions, uniting on each side with their fellows, form a series of arches 
from which are formed, similarly, secondary arches until there are four 
or five tiers of such arches, which progressively diminish in size as they 
near the gut. The terminal arches send numerous straight vessels around 
the gut, 

(c) The ileo-colic divides near the right iliac fossa into two branches. 
The inferior joins the termination of the superior mesenteric ; the upper 
joins the colica dextra. It supplies the ileum, caecum, appendix, and 
ascending colon. 

(d) The colica dextra, to the middle of the ascending colon, divides 
into a lower branch joining the ileo-colic, and an upper, which joins the 
colica media. These branches form arches from which is supplied the 
colon. 

(e) The colica media, to transverse colon, divides into a right branch 
joining the dextra; a left, the sinistra. 

VI. The inferior mesenteric supplies the descending colon and its 
continuation. Arising from the left side of the aorta an inch or two 
above the bifurcation, it passes to the left iliac fossa, ending in the pelvis 
as the superior hemorrhoidal. It gives off — 

(a) The colica sinistra, to the descending colon, dividing into an upper 
branch joining the media ; a lower, the sigmoid artery. 

(b) The sir/moid, to the flexure, joins the colica sinistra above and the 
superior hemorrhoidal below. 

(c) The superior hemorrhoidal in the meso-rectum, crosses the left 
common iliac artery and vein. It divides into two branches, one on each 
side of rectum, which finally join the middle and inferior hemorrhoidal 
arteries. 

VII. The suprarenals, to the under surface of the suprarenal cap- 
sules, join branches of phrenic and renal arteries. 

VIII. The renal, to the hilus, enters by four or five branches into 
which each vessel divides close to the kidney. They lie between the 
veins in front and the ureters behind. Branches pass to the suprarenal 
bodies and ureter. 

15— A. 



226 SYSTEMIC ARTERIES. 

IX. The spermatic, the ovarian in the female, to the testicles or 
ovaries respectively. Passing behind the peritoneum, they cross the 
ureter and psoas, and in front of the vena cava on the right, each cross- 
ing also the external iliac vessels. In the male the vessel then runs 
through the inguinal canal to the testis, joining the artery of the vas 
deferens. In the female it runs in the broad ligament to the ovary, and 
sends branches to the broad ligament, the tubes, and uterus. 

THE ILIAC ARTERIES AND THEIR BRANCHES. 
Describe the common iliac arteries. 

Each runs downward and outward from the division of the aorta to 
the lumbo-sacral joint, and divides into the external and internal iliacs. 

Relations: each has in front the peritoneum, small intestine, ureter, 
and sympathetic nerve ; the left is crossed by the superior hemorrhoidal 
artery; behind and to the inner side of each is its vein, the right having 
both its own and the left vein between it and the last lumbar vertebra, 
and external to each is the psoas magnus. The right has also the vena 
cava posteriorly. 

Branches : small twigs to the psoas, ureters, and lymphatic glands. 

Describe the internal iliac artery. 

It descends to the upper part of the great sacro-sciatic foramen, and 
divides into an anterior and a posterior trunk. 

Relations: in front, ureter and peritoneum; behind, sacrum, lumbo- 
sacral cord, companion vein, and the external iliac vein at its upper part ; 
internally, the vein ; externally, psoas muscle. 

Name and describe its branches. 

The artery divides into two main trunks, the anterior and posterior. 
The posterior gives off the following branches : 

(a) The ilio-lumbar, dividing behind the psoas into an iliac and a 
lumbar branch. The former supplies the iliaeus and a nutrient branch 
to the bone. The latter supplies the psoas and quadratus, as well as 
the cord, by a spinal branch entering the last intervertebral foramen. 
It joins the last lumbar artery. 

{b) The lateral sacral, upper and lower, unite with the middle 
sacral arteiy, and also give branches which enter the foramina supplying 
the contents of the sacral canal, and, emerging at the posterior foramina 
to supply the muscles and skin over the sacrum, join the sciatic and 
gluteal branches. 

(c) The gluteal, through the great sciatic foramen, divides into a su- 
perficial and a deep branch. In the pelvis it gives off muscular branches 
and a nutrient artery to the ilium. 

The superficial branch breaks up into twigs which ramify in the glu- 
tens maximus. The deep subdivides into two others. Of these, one 
runs along the upper border of the gluteus minimus to the anterior su- 



THE ILIAC ARTERIES AND THEIR BRANCHES. 227 

perior spine, joining the circumflex iliac; and the lower branch passes 
toward the great trochanter, giving a twig to the hip-joint and joining 
the external circumflex artery. 

The anterior trunk of the internal iliac supplies the following: 

(</) The superior vesical represents the pervious part of the fetal 
hypogastric artery. It runs to the apex and body of the bladder and to 
the ureter, joins its fellow, and gives off the artery of the vas deferens, 
which accompanies that structure to the testis. It also generally gives 
off the (e) middle vesical to the base of the bladder. 

(/) The inferior vesical— vaginal in the female— joins its fellow. 
It supplies the bladder, prostate gland, and seminal vesicles ; in the fe- 
male, vagina and rectum. 

(g) The middle hemorrhoidal arises with the preceding, and runs 
to the rectum to join other hemorrhoidal arteries. 

(/<)_ The uterine ascends in the broad ligament from the cervix along 
the side of the uterus and joins the ovarian artery. 

(/) The obturator runs forward below the pelvic brim, between the 
peritoneum and pelvic fascia below the nerve, then through the upper 
part of the obturator foramen, dividing beneath the obturator externus 
into an external and an internal branch. Skirting the edges of the fora- 
men, they join below with each other and the internal circumflex. The 
external also joins the sciatic, and sends a branch along the ligamentum 
teres, through the cotyloid notch, to the joint, 

In the pelvis an iliac branch to the bone and iliacus, a pvhic branch to 
the back of the pubes, joining its fellow and the pubic of the epigastric, 
and a vesical branch, are given off from the main trunk of the obturator 
artery. 

The termination of the anterior trunk of the internal iliac then divides 
into two branches, the sciatic and internal pudic arteries. 

(j) The internal pudic escapes from the pelvis through the great 
sciatic foramen, crosses the ischial spine, and re-enters the pelvis by the 
lesser foramen, then runs along the outer wall of the ischio-rectal fossa 
an inch and a half above the tuberosity, and upon the rami of the ischium 
and pubes, to the subpubic arch, where it divides into the artery of the 
corpus cavernosum and the dorsal artery of the penis. 

This vessel is at first in front of the pyriformis, the sacral plexus inter- 
vening, and external to the rectum. Ori the ischial spine it lies beneath 
the gluteus maximus, the pudic nerve internally. In the ischio-rectal 
fossa it lies on the obturator internus, ensheathed by the obturator fas- 
cia, then between the layers of the perineal fascia. 

Branches: (a) two or three inferior hemorrhoidal, to skin and muscles 
around anus. 

(6) The superficial perineal runs over or under the tranversus perinei 
to the back of the scrotum, sending branches to the skin and muscles of 
the perineum. 

(c) The transverse perineal, to the parts between the anus and bulb, 
joins its fellow. 



228 SYSTEMIC ARTERIES. 

(<7) The artery of the bulb runs in the constrictor urethrse, pierces the 
bulb, and sends a branch to Cowpers gland. 

(e) The artery of the corpus cavemoswm runs forward in the centre of 
that body after piercing the crus penis. 

(/) The dorsal artery of the penis runs between symphysis and crus 
penis, pierces the suspensory ligament, and runs along the dorsum of 
the penis to glans and prepuce. Here it is superficial, and lies between 
the median vein and the corresponding nerve. 

In the female the pudic artery is smaller, but has analogous branches. 
The superficial perineal artery runs to the labia ; that of the bulb, to the 
bulbus vestibuli ; that of the corpus cavernosum to the corresponding 
part of the clitoris ; and the dorsal artery to the glans clitoridis. 

[g) The sciatic accompanies the pudic, resting on the py»iformis 
muscle and the sacral plexus, escapes by the great foramen, and de- 
scends, midway between the tuber ischii and the trochanter major, with 
the sciatic nerves. It is covered by the gluteus maximus, and joins the 
superior perforating, obturator, and internal circumflex arteries. 

The branches are — 

{a) The coccygeal, piercing the great sciatic ligament to supply the 
gluteus maximus and the skin over the sacrum and coccyx. 

{b) The muscular, to the gluteus maximus, joining the other gluteal 
arteries within the substance of the muscle. 

(c) The comes nervi ischiadici, in the substance of the great sciatic 
nerve. 

(d) The anastomotic, to the muscles on the back of the hip, anasto- 
mosing with the superior perforating, internal circumflex, and gluteal 
arteries. 

(e) The articular branches, to the capsule of the hip-joint, from the 
above. 

Describe the external iliac artery. 

It extends from the division of the common iliac to the mid-point be- 
tween the crest of the pubes and the anterior superior spine of the ilium, 
behind Poupart's ligament. 

Relations : in front, peritoneum, subperitoneal fascia, sigmoid flexure 
on left, ileum on right side, lymphatic vessels and glands, spermatic or 
ovarian vessels, deep circumflex iliac vein, genital branch of genito- 
crural nerve and, at times, ureter; behind, psoas muscle and iliac fascia 
and its vein ; internally, its vein and the vas deferens ; externally, psoas 
and iliac fascia. 

Name and describe its branches. 

{a) The deep epigastric descends to Poupart's ligament, then as- 
cends, internal to the deep ring, between the transversalis fascia and the 
peritoneum. It then pierces the fascia and enters the sheath of the 
rectus, ascending on the posterior surface of the muscle, and dividing 



ARTERIES OF LOWER EXTREMITY AND BRANCHES. 229 

into brandies which join the superior epigastric. The vas deferens in 
the male, round ligament in the female, cross the vessel on its outer side 
at the internal ring. 

Branches : the cri masteric, to cord ; the pubic, to back of pubes, join- 
ing pubic of obturator; and the muscular. 

(b) The deep circumflex iliac passes to the anterior superior spine 
in a sheath of the transversalis and iliac fascia, thence along inner mar- 
gin of the crest, finally joining branches of the gluteal and of the ilio- 
lumbar arteries between the internal oblique and the transversalis. An 
ascending branch, between the same two muscles, joins the deep epigastric. 

ARTERIES OF THE LOWER EXTREMITY AND THEIR 
BRANCHES. 

Describe the femoral artery. 

It continues the external iliac artery down into the thigh to end at 
the opening in the adductor magnus at the junction of the upper three- 
fourths and lower one-fourth of the femur. Its upper part lies in Scarpa's 
triangle, bounded above by Poupart's ligament, the inner side formed by 
the adductor longus, the outer by the sartorius. The lower part runs in 
Hunter's canal, a depression between the vastus internus and the adduc- 
tores magnus and longus, covered by a strong fascia passing between 
them. 

Relations: in front, fascia lata, crural sheath, fascia covering Hunter's 
canal, sartorius, internal cutaneous and long saphenous nerves, nerve to 
vastus internus, and filaments of the crural branch of genito-crural nerve ; 
behind, psoas magnus, pectineus, adductores brevis, longus, and magnus, 
femoral vein and profunda vessels, branch of the anterior cruraf nerve 
to pectineus ; outer side, anterior crural nerve, vastus internus, and fem- 
oral vein below; inner side, sartorius, adductor longus, femoral vein 
above. 

Name and describe its branches. 

(a) The superficial epigastric, through the saphenous opening, 
ascends in the superficial fascia over the abdomen, joining other epi- 
gastrics. 

(b) The superficial circumflex iliac, parallel with Poupart's liga- 
ment to crest of ilium, joins deep circumflex and gluteal. 

(c) The superior external pudic crosses to the lower abdomen 
over the cord, supplying the penis and scrotum (to labium in female), 
and joins the internal pudic terminal branches. 

(d ) The inferior external pudic crosses the pectineus, pierces the 
fascia lata, and supplies the perineum and scrotum (labium in female), 
joining the perineal arteries. 

(e) The muscular branches all along its course. 

If) The anastomotica magna arises close to the adductor open- 
ing, and divides into two branches : a deep, to the inner side of the 



230 SYSTEMIC ARTERIES. 

knee, joins the recurrent tibial and articular arteries, and a superficial 
which runs with the long saphenous nerve. 

(.</) The profunda artery arises from the femoral at its outer and 
back part, 1 to 2 inches below Poupart's ligament. It at first runs out- 
ward, but afterward behind the femoral, then beneath the adductor 
longus, terminating at the lower third of the thigh by piercing the ad- 
ductor niagnus, becoming the lowest perforating artery. 

Relations : in front, adductor longus, femoral and profunda veins ; 
behind, iliacus, pectineus, adductores niagnus and brevis. 

Branches: the external circumflex runs beneath the sartorius and 
rectus, and divides into — ascending branches, under the tensor vaginas to 
join the gluteal and deep circumflex iliac arteries ; descending branches, 
running upon the vasti, some passing beneath to the knee, to join the 
articular arteries ; transverse, piercing the vastus externus to the back 
of the femur, and joining the superior perforating. 

The internal circumflex runs between the psoas and pectineus, and 
supplies the adductor and obturator muscles and an articular twig to the 
hip-joint, under transverse ligament. It then joins in the crucial anas- 
tomosis. 

The perforating pierce the short and great adductor muscles to the 
back of the thigh, anastomosing freely with each other and with the 
popliteal below. The superior enters into the crucial anastomosis. The 
first arises above the adductor brevis, the second opposite, the third be- 
low it. The second or third gives the nutrient artery to the femur. The 
termination of the profunda is called the fourth perforating. 

Describe the popliteal artery. 

It runs from the adductor opening to the lower border of the poplit- 
eus, where it divides into the anterior and posterior tibial. 

Relations : in front, femur, ligamentum posticum, popliteus ; behind, 
semimembranosus, fascia, gastrocnemius, plantaris, and soleus, popliteal 
and short saphenous veins, and the internal popliteal nerve ; outer side, 
external condyle, outer head of the gastrocnemius, plantaris, internal 
popliteal nerve above ; inner side, inner condyle, inner head of the gas- 
trocnemius, semimembranosus, popliteal vein, and the internal popliteal 
nerve below. 

Name and describe its branches. 

(a) Muscular superior, three or four, to the lower part of the ham- 
string muscles to join the inferior perforating ; inferior (sural), to the 
upper part of the gastrocnemius, plantaris, and soleus. 

(b) Cutaneous, to the skin of the calf. 

(c) Articular superior, two in number, an external and an inter- 
nal, wind around above the condyles to the front. The external gives a 
branch to the external vastus and one to the joint, and also forms an 
arch with the anastomotica. The internal gives a branch to the internal 



ARTERIES OF LOWER EXTREMITY AND BRANCHES. 231 

vastus, joining anastomotica and inferior articular, and another to the 
knee-joint, and also unites with the inferior articular. 

((/) The azygos articular pierces the posterior ligament to the 
joint. 

(e) Articular inferior wind around the tibia below the joint. They 
are external and internal, and anastomose with the tibial recurrent, 
anastomotica, and other articular branches. 

Describe the anterior tibial artery. 

It runs from the lower border of the popliteus, between the heads of 
the tibialis posticus and above the interosseous membrane, to the front 
of the leg, then descends as far as the ankle, ending in the dorsalis 
pedis, 

Relations : in front, integument, fasciae, tibialis anticus, extensores 
proprius pollicis and longus digitorum, anterior tibial nerve; behind, 
interosseous membrane, tibia, anterior tibio-tarsal ligament ; outer side, 
extensores proprius pollicis and longus digitorum, anterior tibial nerve ; 
inner side, tibialis anticus, extensor proprius pollicis. 

Name and describe its branches. 

{a) The recurrent tibial, through the tibialis anticus to the knee, 
joins other articular arteries. 

(b) The muscular, to the muscles and skin ; very numerous. 

(c) The malleolar, to the^ ankle-joint. Internal joins corresponding 
branches of the posterior tibial ; external joins the tarsal and anterior 
peroneal. 

Describe the dorsalis pedis. 

It is the continuation of the anterior tibial, and runs from the bend 
of the ankle to the first interosseous space, where it divides into the 
dorsalis al/icis and plantar digital. 

Relations: in front, skin, fascia, inner tendon of extensor bre vis digi- 
torum ; behind, tarsal bones and their ligaments ; tibial side, extensor 
proprius ; fibular side, extensor longus digitorum, anterior tibial nerve. 

Name and describe its branches. 

(a) The tarsal, beneath the short extensor, supplying it and the 
tarsus and joining metatarsal and peroneal arteries. 

lb) The metatarsal, over the bases of the metatarsal bones, joins 
the tarsal and external plantar, and gives off three dorsal interosseous 
arteries which run in the outer three intermetatarsal spaces, each di- 
viding opposite the metatarso-phalangeal joint into two dorsal digital 
branches. These arteries anastomose at back part of spaces with the 
posterior perforating, and at front part with the anterior perforating. 

(c) The dorsalis allicis lies along the first intermetatarsal space, and 
supplies both sides of the great toe and the inner side of the second 
dorsally. 



232 SYSTEMIC AETERIES. 

[d ) The plantar digital passes between the heads of the first dorsal 
interosseous, joins with the external plantar to form the plantar arch, 
and after supplying inner side of great toe divides into two branches for 
the adjacent sides of the great and second toes. 

Describe the posterior tibial artery. 

It runs from the lower border of the popliteus to divide, between 
inner malleolus and heel, into the external and internal plantar arteries. 

Relations: in fronts tibialis posticus, flexor longus digitorum, tibia, 
and ankle-joint; behind, skin, fascia, gastrocnemius, soleus, deep trans- 
verse fascia, posterior tibial nerve. This nerve is internal in its upper 
part, but lower down it is external to the artery. 

Name and describe the branches of the posterior tibial artery. 

(a) The peroneal runs from 1 inch below the popliteus to the lower 
third of the leg, and divides into the anterior and posterior peroneal. It 
is covered by the soleus and deep transverse fascia ; in front of it are 
the tibialis posticus and interosseous membrane ; external to it, the fib- 
ula ; and externally, as well as behind, the flexor longus pollicis. 

The peroneal gives off muscular branches and a nutrient artery to the 
fibula. The anterior peroneal passes beneath the interosseous membrane 
to the front of the leg, and runs to the outer ankle to join the tarsal 
and external malleolar. The posterior peroneal passes down behind the 
external malleolus, and terminates in branches [external calcaneal) which 
anastomose with the external malleolar. 

(b) The nutrient artery for the tibia, from the posterior tibial close 
to its origin, is the largest nutrient artery of bone in the body. 

(c) The muscular branches to the calf-muscles. 

(at) The communicating-, crossing back of the tibia to join the 
peroneal artery. 

(e) Several internal malleolar, which join the inner malleolar of 
the anterior tibial. 

Describe the plantar arteries. 

They are the terminal branches of the posterior tibial. The internal 
is at first under cover of the abductor pollicis, and then between it and 
the flexor brevis digitorum, anastomosing at the inner border of the 
great toe with its digital artery. 

The external, the larger, passes to the base of the fifth metatarsal, 
then to the space between the first and second metatarsals, and joins the 
plantar digital, from the dorsalis pedis, to form the plantar arch. 

Describe the plantar arch. 

It supplies the muscles, fascia, and skin of the sole of the foot, and 
gives off the posterior perforating. These pierce the three outer spaces 
between the heads of the dorsal interossei and join the dorsal interos- 
seous arteries. 



THE SYSTEMIC VEINS. 233 

The digital^ four in number, supply the three outer toes and the outer 
half of the second toe : the first runs to the outer side of the little toe, 
the others bifurcate to the adjacent sides of the fourth and fifth, fourth 
and third, third and second toes. At the point of bifurcation each sends 
a small branch to join the dorsal interosseous arteries [anterior per- 
forating). . 

THE VEINS. 

THE PULMONARY VEINS. 
Describe the pulmonary veins. 

These are four large trunks, two on each side, which return the blood 
from the lungs to the left auricle. On the right side they pass behind 
the right auricle and superior vena cava ; on the left, in front of the 
descending aorta. The upper right vein t receives the branch from the 
middle lobe. 

THE SYSTEMIC VEINS. 

Describe the veins of the heart. 

The great cardiac vein ascends in the anterior interventricular 
groove from the apex of the heart to the left auriculo-ventricular 
groove ; along this latter it runs to the posterior surface of the heart, 
to end in the coronary sinus! At its termination it is provided with a 
valve. 

Three or four posterior cardiac veins ascend on the left ventricle 
to the sinus. 

The middle cardiac vein ascends in the posterior interventricular 
groove to the sinus. 

The right (small) coronary vein in the right auriculo-ventricular 
groove to the sinus. 

The coronary sinus, 1 inch long, is placed at the back part of the 
auriculo-ventricular groove, on the left side, and opens into the right 
auricle in front of the inferior vena cava. Besides the foregoing veins, 
it receives the oblique vein of Marshall, which drains the back of the 
left auricle. Its opening is guarded by the Thebesian valve. 

The other cardiac veins are several small vessels from the front of the 
right ventricle, the anterior cardiac veins, opening directly into the 
auricle, and the vense Thebesii, in the muscular substance, which 
open by minute orifices, the foramina Thebesii, near the septum auricu- 
larum. 

SUPERIOR VENA CAVA AND INNOMINATE VEINS. 
Describe the superior vena cava. 

This large trunk is formed by the union of the two vense innominatae, 
and returns the blood from the head and neck, the thoracic walls, and 



234 THE SYSTEMIC VEINS. 

the upper extremities. It is about 3 inches long, and descends from 
the junction of the first right cartilage with the sternum to its termina- 
tion in the right auricle, opposite the upper border of the third right 
cartilage. 

At first it is external to the innominate artery and internal to the right 
phrenic nerve, partly covered by the pleura. It then pierces the peri- 
cardium external to the ascending aorta, having descended in front of 
the right division of the pulmonary artery. It receives the azygos 
major and small pericardiac and mediastinal veins. 

Describe the innominate veins. 

The innominate veins, formed by the union of the subclavian and in- 
ternal jugular of each side, behind the inner end of the clavicle unite 
to form the superior vena cava. The right vein, 1 inch long, descends 
vertically on the right side of the innominate artery, while the left, more 
than 2 inches in length, descends slightly, running to the right, behind 
the sterno-hj^oid and thyroid muscles and upper part of sternum. The 
transverse aorta lies below it. 

What are the tributaries of the innominate veins ? 

On each side the vertebral, inferior thyroid, and internal mammary 
veins. The left vein also receives the superior intercostal and some 
small thymic, mediastinal, and pericardiac veins and the thoracic duct, 
while the right is joined at its origin by the right lymphatic duct. 

Describe the vertebral vein. 

This vein descends with the artery through the foramina in the trans- 
verse processes of the upper six cervical vertebrae, crosses the subclavian 
artery, and opens into the back part of the vena innominata. 

It receives branches: from the muscles in its course and from the 
spinal canal through the intervertebral foramina ; a small vein which 
accompanies the superior^ intercostal artery, as well as the anterior verte- 
bral and deep cervical veins. 

The anterior vertebral arises from the plexus over the cervical part of 
the spine, and runs along with the ascending cervical artery. The deep 
cervical arises in the suboccipital triangle, runs between the complexus 
and semispinalis and below the transverse process of the seventh cervi- 
cal vertebra to the vertebral vein. It receives branches from the deep 
spinal muscles, and the occipital veins empty into it. 

Describe the inferior thyroid veins. 

These arise by branches from the lateral lobes of the thyroid gland, 
and descend on the trachea beneath the stemo-thyroid muscles. They 
anastomose with the superior and middle thyroid veins, and receive 
oesophageal^ laryngeal, and tracheal branches. The left joins the in- 
nominate on its own side, sometimes in common with the right, The 



VEINS OF THE HEAD AND NECK. 235 

latter may empty into the junction of the two venae innominatae or join 
the right vena innominata. 

Describe the internal mammary veins. 

These are two on each side, and accompany the artery, receiving cor- 
responding branches, finally uniting to form a single trunk which joins 
the corresponding innominate. 

Describe the superior intercostal vein. 

It drains the two or three spaces below the first, and enters on the 
right side the large azygos ; on the left side it communicates with the 
left upper azygos and joins the innominate. 

VEINS OF THE HEAD AND NECK. 
Describe the facial vein. 

The facial vein runs from the inner angle of the eye to the anterior 
border of the masseter muscle, then backward below the jaw, joining 
the anterior division of the temporo-maxillary trunk to form the common 
facial, which joins the internal jugular. It sends a communicating branch 
along the front of the sterno-mastoid to the anterior jugular. At its ori- 
gin it is continuous with the angular, a vein formed by the union of the 
frontal and supraorbital. 

The fronted runs from the forehead, parallel with its fellow and joined 
with it by cross-branches, to the inner side of the orbit, and joins the 
supraorbital, which drains the forehead, eyebrow, and upper lid, com- 
municating with the temporal and ophthalmic veins. 

The angular vein runs down and alongside of the nose near its root. 
It receives some superior palpebral and nasal veins, and communicates 
with the ophthalmic, becoming continuous with the facial. 

The facial vein, in addition, receives the following tributaries : 

Several inferior palpebral veins communicating with the infraorbital ; 

The superior labial vein and small buccal and masseteric twigs ; 

The deep faded from the pterygoid plexus, as well as some parotid 
veins ; 

The submental, receiving the veins from the lower lip and submaxil- 
lary gland and communicating with the anterior jugular vein ; 

The submaxillary veins from the gland, and the inferior palatine vein 
from the plexus around the tonsil and soft palate. 

Describe the temporo-maxillary vein (posterior facial). 

This short trunk, formed by the temporal and internal maxillary veins, 
runs from opposite the condyle of the lower jaw to the angle of the 
jaw, and divides into an anterior branch joining the facial and a poste- 
rior branch running backward to form with the posterior auricular the 
external jugular. This vein is imbedded in the parotid gland external 
to the external carotid artery. 



236 THE SYSTEMIC VEINS. 

Describe the temporal vein. 

The temporal is formed by the union of the superficial with the 
middle temporal vein, and crosses over the zygoma and under the paro- 
tid to join the internal maxillary vein. It receives the anterior auricu- 
lar, parotid, and transverse facial veins, and tributaries from a plexus 
around the articulation of the jaw. 

The superficial temporal arises from a plexus at the side of the head 
from which proceed branches similar to those of the artery. These join 
to form the vein. 

The middle temporal vein arises from a plexus in the temporal fossa, 
pierces the fascia near the zygoma, and joins the above. This vein 
receives an orbital branch and several external palpebral veins. 

Describe the internal maxillary vein. 

The internal maxillary vein arises from the pterygoid plexus and 
runs in company with the first part of the artery, joining the temporal 
vein behind the ramus of the jaw. 

The pterygoid plexus corresponds to the second and third parts of die 
internal maxillary artery. It covers both pterygoid muscles, and receives 
veins corresponding to the branches of the artery — namely, several deep 
temporal, an alveolar, inferior dental, two middle meningeal, superior 
palatine, infraorbital, and spheno-palatine, and a communicating vein 
from the inferior ophthalmic. The blood leaves by the deep facial and 
the internal maxillary veins. 

Describe the posterior auricular and occipital veins. 

The posterior auricular vein descends over the mastoid process 
and sterno-mastoid and ends in the external jugular. 

The occipital veins, two or three, join the deep cervical vein. 

The emissary vein in the mastoid foramen connects the lateral sinus 
with the most external of the occipital veins. 

Describe the external jugular vein. 

It is formed by the union of the posterior auricular and the posterior 
division of the temporo-maxillary trunk. It descends obliquely across 
the sterno-mastoid, lying between the platysma and fascia. Above the 
clavicle it pierces the fascia and joins the subclavian at the outer border 
of the scalenus anticus ; sometimes it joins the internal jugular. It re- 
ceives the posterior external jugular, anterior jugular, transverse cervi- 
cal, and suprascapular veins. The two latter correspond to the arteries 
of the same name. 

The posterior external jugular drains the occipital and posterior cervi- 
cal regions. 

The anterior jugular descends along the front of the neck from the 
submaxillary region, pierces the fascia near the inner end of the clavicle, 
and joins the external jugular, sometimes the subclavian. This vein and 
its fellow are joined by a cross-branch just above the sternum, and it 



VEINS OF THE HEAD AND NECK. 237 

receives brandies of communication from the submental, external jugu- 
lar, and facial. 

Describe the internal jugular vein. 

This vein commences at the jugular foramen just below the junction 
of the inferior petrosal with the lateral sinus, and descends with the in- 
ternal carotid, then with the common carotid, to join at a right angle 
with the subclavian vein behind the clavicle, thus forming the innomi- 
nate vein. It is placed external to the carotid vessels, lying in the 
same sheath with each in turn. 

It receives the following tributaries : 

The common facial {ride an tea) and the middle thyroid. 

The superior thyroid, which receives the superior laryngeal and crico- 
thyroid., and sometimes joins the common facial. 

The pharyngeal veins. These form a plexus on the outer side of the 
pharynx, from which several veins descend to join the internal jugular 
or common facial. Branches pass to join the pterygoid plexus. 

The lingual veins, including the raitine, dorsal vein of the tongue, and 
the vencv comites of the lingual artery. 

(The inferior petrosal sinus is regarded by some anatomists as the first 
tributary. ) 

Describe the cerebral veins. 

These are divided into two sets, the superficial and the deep. 

Superficial veins : the superior, ten to twelve on each side, consist 
of the anterior, middle, and posterior veins which run in the sulci, and, 
joining with branches from the mesial aspect of the brain, empty into 
the superior longitudinal sinus. The inferior consist of the middle cere- 
bral vein, in the Sylvian fissure, which joins the cavernous sinus, and the 
great anastomotic vein, in the posterior branch of the same fissure, com- 
municating with the middle meningeal veins and joining the superior 
petrosal sinus. 

Deep veins : they finally converge to two trunks, the vence Galeni. 
These run backward in the velum interpositum, the right and left, lying 
side by side, and unite into the vena magna Galeni, which joins the 
straight sinus. Each vena Galeni is formed by the union of the choroid 
vein and the vena corporis striati, and is joined by the basilar and other 
small veins, while the vena magna receives tributaries from the occipital 
lobes of each side and from the upper surface of the cerebellum. 

Describe the cerebellar veins. 

The superior join the straight sinus and the vena magna internally, 
and the superior petrosal and lateral sinuses externally. 

The inferior enter the inferior petrosal, lateral, and occipital sinuses 
along with branches from the medulla and pons. 



238 THE SYSTEMIC VEINS. 

Describe the cranial sinuses. 

(1) The superior longitudinal sinus is contained in the upper 
border of the falx cerebri, and extends from the crista galli to the tor- 
cular Herophili. Its section is triangular, and its cavity is crossed by 
several fibrous bands, the chordae Willisii, and contains some Pacchio- 
nian bodies. It grooves the frontal, parietal, and occipital bones. In 
front a small vein in the foramen caecum connects it with the nasal veins, 
and through the parietal foramen it communicates with the veins of the 
scalp. The superior cerebral veins open into the sinus, looking forward 
contrary to the direction of the blood-current. At its termination it en- 
larges and becomes continuous with the right (usually) or left lateral 
sinus. From this dilatation (the torcular Herophili) a cross-branch 
passes to join the straight sinus. 

(2) The* inferior longitudinal sinus, in the lower border of the 
falx cerebri, runs back to join the straight sinus. 

(3) The straight sinus continues the inferior longitudinal along the 
line of junction of the falx with the tentorium backward, and joins the 
lateral sinus opposite to that in which the superior longitudinal ends. 
It receives the vena magna Galeni, some superior cerebellar veins, and a 
cross-branch from the torcular Herophili. 

(4) The lateral sinuses run in the attached margin of the tento- 
rium from the internal occipital protuberance to the jugular foramen, 
grooving, in order, the occipital, parietal, mastoid portion of the tem- 
poral, and the occipital a second time. Each sinus receives the supe- 
rior petrosal sinus and emissary veins from the mastoid and posterior 
condylar foramina, as well as some cerebellar, diploic, and posterior 
cerebral veins. 

(5) The occipital sinus, small, sometimes double, is contained in 
the falx cerebelli, and opens into the torcular above and the lateral sinus 
below by a branch on each side of the foramen magnum. It receives 
some cerebellar veins and branches from the posterior spinal veins. 

(6) The cavernous sinuses, one on each side of the body of the 
sphenoid, run from the sphenoidal fissure, to the apex of the petrous 
portion of the temporal, receiving the ophthalmic veins in front and 
joining the petrosal sinuses behind. It receives the spheno-parietal 
sinus, some inferior cerebral veins, and is joined with the opposite 
vessel by the circular sinus. 

(7) The circular sinus consists of the anterior and posterior inter- 
cavernous sinuses, which join at each end the cavernous sinuses, thus 
surrounding the pituitary body. 

(8) The superior petrosal sinus runs from the cavernous sinus, 
along the upper border of the petrous portion of the temporal, to end 
in the lateral sinus at the fossa sigmoidea. It receives the inferior cere- 
bral, superior cerebellar, and some tympanic veins. 

(9) The inferior petrosal, in the groove between the basilar process 
and petrous portion, runs from the cavernous to join the lateral sinus at 



VEINS ON THE HEAD AND NECK. 239 

the jugular foramen, completing the internal jugular vein. (See under 
Internal Jugular Vein. ) It receives the auditory and some inferior cere- 
bellar veins. 

(10) The transverse (basilar) sinus is a plexus in the dura mater 
over the basilar process. It joins the anterior spinal veins below and 
the two interior petrosal sinuses laterally. 

Describe the ophthalmic veins. 

The superior passes back from the root of the nose with the oph- 
thalmic artery through the sphenoidal fissure to the cavernous sinus. 
At its origin it connects with the angular and supraorbital veins, and 
receives the ethmoidal, muscular, and lachrymal, vena centralis retinae, 
anterior, and some of the posterior ciliary veins. 

The inferior runs back, near the floor of the orbit, to open into the 
cavernous sinus, sometimes joining the superior. It arises by the union 
of some muscular and posterior ciliary veins, and is connected with the 
pterygoid plexus by a branch through the spheno-maxillary fissure. 

Describe the diploic veins. 

They run between the tables of the skull and open into the dural 
sinuses or externally. The larger consist, on each side, of a frontal, 
through an aperture in the supraorbital notch, joining the supraorbital 
vein ; an occipital, to the occipital veins or torcular ; and two temporal 
— the anterior, through an aperture in the great wing of the sphenoid 
to join a deep temporal vein, and the posterior, through a foramen in 
the parietal bone to the lateral sinus. 

What are the emissary veins ? 

These small veins connect the cranial sinuses with the veins outside 
by means of foramina in the bones. These are the principal : one 
each — 

(a) Through mastoid foramen, from lateral sinus to outermost occip- 
ital vein. 

(ft) Through posterior condylar foramen, from lateral sinus to cervical 
venous plexus. 

(c) Through parietal foramen, from superior longitudinal to veins of 
scalp. 

(d) Through a foramen in external occipital protuberance to occipital 
veins. 

(e) Through foramen ovale, from cavernous to pterygoid plexus. 

(/) Through foramen lacerum medium, from cavernous sinus to 
pharj 7 ngeal plexus. 

[g) Through carotid canal, a small plexus from cavernous sinus to 
internal jugular. 

(/?) Through anterior condylar foramen, a plexus from occipital sinus 
to deep cervical veins. 



240 THE SYSTEMIC VEINS. 

VEINS OF THE UPPER EXTREMITY. 
Describe the superficial veins. 

They commence from a plexus on the dorsum of the hand mostly, but 
to some extent from the palm. They comprise the following : 

The ulnar, anterior and posterior, occupy corresponding positions on 
the inner side of the forearm, and unite above in the common ulnar. 

The radial vein is situated on the outer side, and the median as- 
cends mesially, receives a deep median vein, and divides at the bend of 
the elbow into the median basilic and median cephalic. 

The median basilic joins the common ulnar to form the basilic. 
The bicipital fascia separates it from the brachial artery. 

The median cephalic crosses the external cutaneous nerve, and 
joins the radial to form the cephalic. 

The basilic runs along the inner side of the biceps, pierces the fas- 
cia, and is continued upward into the axillary vein. 

The cephalic runs along the outer side of the biceps, then between 
the pectoralis major and deltoid, piercing the costo-coracoid membrane 
to join the axillary vein below the clavicle. 

Describe the deep veins. 

The deep veins of the upper extremity are the venae comites. They 
run one on each side of its artery from the digital to the brachial arteries. 
The venae comites of the latter vessel, at the lower border of the sub- 
scapulars muscle, empty into the axillary vein. 

The axillary vein runs internal to the artery, and receives veins cor- 
responding to its branches, as well as the cephalic. 

The subclavian vein is the continuation upward of the axillary, and 
runs, at a lower level than its artery, from which it is separated by the 
phrenic nerve and scalenus anticus, to the inner border of that muscle, to 
join the internal jugular, forming the innominate. It receives the ex- 
ternal jugular, and occasionally the anterior. 

VEINS OP THE TRUNK. 
Describe the azygos veins. 

The right or vena azygos major commences by the right ascend- 
ing lumbar vein. Ascending to the thorax through the aortic opening 
and on the bodies of the dorsal vertebrae to the fourth, it arches over 
the root of the right lung and joins the superior vena cava above the 
pericardium. It receives the right sup. intercostal vein and the remain- 
ing right intercostal veins save the first, the left azygos, the right bron- 
chial, and some oesophageal, posterior mediastinal, and pericardiac veins. 
Below it communicates with the common iliac by means of the ascend- 
ing lumbar. 

The left lower (small) azygos vein commences as the left ascending 
lumbar, and ascends through the left crus and along the spine to the 



VEINS OF THE TRUNK. 241 

ninth dorsal vertebra. It then crosses to the right, behind the aorta, 
and joins the vena azygos major. It receives the lower three or four 
mtercostals and some mediastinal veins. 

The left upper azygos vein is formed by the fourth intercostal to 
the eighth, inclusive, and joins the large azygos. It receives the medi- 
astinal branches, left bronchial vein, and communicates above with the 
left superior intercostal. 

The intercostal veins lie above the arteries. The first joins the innom- 
inate or vertebral ; the rest join the azygos veins, the two or three 
upper uniting to form the superior intercostal. They receive branches 
from the vertebrae and the adjacent muscles. 

The bronchial reins return part of the blood from the bronchial arte- 
ries. The right joins the vena azygos major; the left, the left upper 
azygos. 

Describe the spinal venous system. 

{a) The dorsal spinal veins, from the skin and muscles, form a 
plexus over the arches of the vertebrae, with a median longitudinal ves- 
sel over the spinous processes. Branches pass to the intercostal, lumbar, 
and vertebral veins. 

(b) The vense basis vertebrae run in canals in the bodies of the 
vertebrae, and emerge by a single or double orifice into the spinal canal 
to join the transverse branch which connects the anterior longitudinal 
veins. 

(c) The anterior longitudinal spinal veins are two plexiform 
trunks, one on each side of the posterior common ligament throughout 
its whole length. They are dilated opposite the bodies, and joined by 
branches beneath the ligament. Above they communicate with the 
basilar sinus. Branches also pass out at the foramina on each side. 

(d) The posterior longitudinal spinal veins, one on each side, 
run between the dura and the posterior wall of the spinal canal. Cross- 
branches join them, and they communicate with the occipital sinus and 
the dorsal spinal veins, and with the anterior longitudinal by branches 
through the same intervertebral notches. 

(e) The veins of the cord run tortuously in the pia mater, one 
larger vein along the anterior fissure. They join into several trunks 
above, which empty into the cerebellar veins or the inferior petrosal 



Describe the inferior vena cava. 

This large trunk arises at the fifth lumbar, by the union of the two 
common iliacs. It ascends to the right of the aorta, grooves the poste- 
rior border of the liver, pierces the diaphragm, is enclosed by the serous 
la3 T er_of the pericardium, and empties into the right auricle. The Eu- 
stachian valve .guards its orifice. It receives the following tributaries : 

(a) The lumbar, corresponding to the arteries. Each arises by the 
union of an anterior branch from the abdominal wall and a posterior 

16— A. 



242 THE SYSTEMIC VEINS. 

from the dorsal plexus, muscles, and spinal canal. They run inward, 
beneath the psoas muscles, and on the left side behind the aorta, and 
open into the back of the inferior vena cava. Above and below, cross- 
branches unite these veins, forming the ascending lumbar, which is con- 
tinued up into the azygos vein. This last also connects together the ilio- 
lumbar, lateral sacral, and common iliacs. 

(b) The spermatic forms within the spermatic cord a plexus, the 
spermatic or pampiniform, which runs with the spermatic artery through 
the inguinal canal, ending in several vessels uniting into a single trunk. 
This vein, the spermatic, ascends on the psoas behind the peritoneum, 
and joins the vena cava on the right, the renal vein on the left side. 

In the female its analogue, the ovarian vein, forms the pampiniform 
plexus in the broad ligament and runs with the artery. 

(c) The renal veins run from the hilus of the kidney, in front of the 
arteries, to join the vena cava at a right angle. The left is longer and 
crosses the aorta. This vein receives some small suprarenal branches 
and also the spermatic and suprarenal veins. 

(d) The suprarenal run from the suprarenal bodies to the vena cava 
on the right, the renal on the left side. 

(e) The inferior phrenic, two on each side, run with their arteries. 
The left pair often joins the suprarenal vein. 

(/) The hepatic veins, two or three, join the vena cava at the 
groove in the liver through which the latter passes. Several smaller 
veins empty separately. They return the blood from the liver brought 
by the portal vein and the hepatic artery. 

Describe the common iliac veins. 

Formed by the junction of the external and internal iliacs, they run 
from the base of the sacrum to the upper part of the fifth lumbar ver- 
tebra, and unite to form the inferior vena cava. The right is the shorter, 
and is at first behind, later to the right, of its artery, while the left is 
internal to its own artery, then behind the right iliac artery. The com- 
mon iliacs receive the following tributaries : 

The ilio-lumbar, from back of the abdomen, muscles, and spinal 
canal, runs beneath the psoas to the lower part of the common iliac. It 
communicates with branches of the lumbar above, lateral sacral below. 

The two middle sacral, one on each side of the artery, anastomose 
with the lateral sacral and hemorrhoidal veins, and unite- into a single 
vessel which joins the left common iliac vein. 

VEINS OF LOWER EXTREMITY. 
Describe the superficial veins. 

On the dorsum of the foot is a plexus which receives the digital veins, 
and forms an arch from which emerge the internal or long and the ex- 
ternal or short saphenous veins. 

The long saphenous, from the inner part of the plexus, runs in 



VEINS OF THE PELVIS. 243 

front of the inner malleolus, along with the long saphenous nerve, be- 
hind the inner border of the tibia and condyle of the femur; thence up 
along the antero-internal part of the thigh to join the femoral vein at 
the saphenous opening. It communicates with the deep plantar, both 
tibial, and the femoral veins, and receives superficial plantar and cuta- 
neous branches, and the superficial circumflex iliac, epigastric, and exter- 
nal mtdic veins. 

The short saphenous vein ascends behind the outer malleolus, and 
external to the tendo Achillis, with the external saphenous nerve, and 

5 tierces the deep fascia in the popliteal space to join the popliteal vein, 
t receives branches from the heel and back of the leg and from the 
deep veins and the long saphenous. 

Describe the deep veins. 

The deep veins are the vence comites of the arteries. The posterior 
tibial veins receive the peroneal, and join the anterior tibial to 
form the popliteal. This vessel then ascends, crossing superficial to 
the artery, from the inner to the outer side, and becomes the femoral at 
the adductor opening. It receives the external saphenous and veins cor- 
responding to the arterial branches. 

The femoral vein accompanies the artery, and becomes the external 
iliac at Poupart's ligament. It is at first outside, then behind, and at 
its termination internal to, the artery. It receives, in its lower part, 
veins corresponding to the branches of the superficial femoral artery ; 
the long saphenous, and the profunda vein. The latter is formed by 
the union of the vence comites of the offsets of the profunda artery. 

The external iliac runs to join the internal iliac near the lumbo- 
sacral articulation, being at first internal to, later behind, the artery. It 
receives the deep circumflex iliac, the deep epigastric, and a pubic vein. 

VEINS OF THE PELVIS. 
Describe the internal iliac vein. 

It accompanies the artery, lying behind and to its inner side, to join 
the external at the base of the sacrum, forming the common iliac. Its 
tributaries correspond to the branches of the artery in a general way. 
Thus, it receives the following : 

.The gluteal, sciatic, and the obturator ; the lettered sacral, which form 
a plexus on the sacrum and open into the internal iliac at several points ; 
the internal pudic, which receives branches corresponding to the perineal 
branches of the artery and commences as the vein of the corpus caver- 
nosa m. 

The dorsal vein of the penis, at first two veins, these uniting into one, 
which runs back between the two dorsal arteries in a median groove, 
passesbelow the subpubic ligament, and divides into two veins, joining- 
each side of the prostatic plexus, and each division communicating with 
the obturator and pudic veins of each side. 



244 THE SYSTEMIC VEINS. 

The visceral veins are larger than the arteries, and communicate freely 
with one another, so as to form a series of plexuses, as follows : 

The prostatic plexus, continuous above with the vesical plexus, is 
formed by the dorsal vein of the penis and branches from the prostate 
and its vicinity. It communicates with the radicles of the pudic vein. 
This plexus has its analogue in the female around the urethra, which 
receives the dorsal rein of the clitoris. 

The vesical plexus extends over the body and base of the bladder, and 
communicates with the prostatic and hemorrhoidal plexuses ; vaginal in 
female. 

The hemorrhoidal plexus, in the wall of the lower rectum, beneath 
the mucous coat, sends out superior, middle, and inferior hemorrhoidal 
veins, which follow the corresponding arteries, and communicates freely 
with the other plexuses. 

The vaginal plexus surrounds the lower part of the vagina, and com- 
municates with the vesical and hemorrhoidal plexuses, and the uterine 
plexus empties into the ovarian vein. 

THE PORTAL SYSTEM. 
Describe the portal system of veins. 

The portal vein, 3 inches long, arises from the union of the splenic 
and superior mesenteric veins behind the head of the pancreas, and as- 
cends behind the duodenum and between the layers of the lesser omen- 
tum. Here it runs behind hepatic artery and bile-duct, Accompanied 
by the hepatic plexus of nerves and lymphatics, all enclosed in Glisson's 
capsule, it then enters the transverse fissure, forming near the right 
end the "sinus," and divides into: a right branch, to the right lobe, 
which distributes branches entering the hepatic substance with hepatic 
arterial branches and ducts ; and a left branch distributed like the right. 
To it are joined the obliterated umbilical vein and the ductus venosus. 

The vena portae receives the following tributaries : 

The superior mesenteric, corresponding to the artery of the same 
name, receiving also the right gastro-epiploic vein, besides branches ac- 
companying those of the artery. It joins the splenic vein. 

The splenic arises by five or six vessels uniting after leaving the 
hilus, and runs to the right below the artery, joining the above at a 
right angle to form the vena portae. It receives the vasa hrevia. left 
(jostro-epiploic, and pancreatic branches, and sometimes the inferior 
mesenteric vein. 

The inferior mesenteric vein co?"responds in branches and course 
to the artery, and empties into the angle of junction of the two pre- 
ceding. 

The pyloric runs with the pyloric branch of the hepatic artery, and 
joins the vena portae ; also the vena coronaria ventriculi, running 
with the gastric artery and receiving oesophageal branches, joins the 
vena portae above the former. 



THE ABSORBENT SYSTEM. 245 



THE ABSORBENT SYSTEM. 

The absorbent system consists of vessels resembling thin-walled veins, 
the lymphatics, interrupted at intervals by t lie lymphatic glands. The 
lymphatics of the alimentary canal are called lacteal*. All these ves- 
sels converge to two principal trunks, the thoracic duct and the right 
lymphatic dint, which open into the large veins at the root of the 
neck. 

Describe the thoracic duct and right lymphatic duct. 

The former begins by a dilatation, the receptaculum chyli, at the second 
lumbar vertebra, where the lacteals and lower lymphatics unite. It is 
placed behind or to the right side of the aorta at its origin, and ascends 
between it and the right cms to the thorax, lying on the front of the 
dorsal vertebrae, between the aorta and vena azygos major. It then 
runs upward toward the left, behind the arch of the aorta (at the fourth 
dorsal v.), then between the oesophagus and left subclavian artery, and 
at the seventh cervical vertebra it arches over the pleura to join the 
angle of union between the left subclavian and internal jugular veins. 
It receives the absorbents from the whole body excepting those of the 
right upper limb and right half of the head, neck, chest, heart, part 
of the upper surface of the liver and right lung. 

The right lymphatic duct collects the lymph from the parts just 
mentioned above. It is only % an inch or less in length, and empties on 
the right side, at a point corresponding to that where the thoracic duct 
empties on the left side. 

Describe the lymphatics and lymphatic glands of the lower limb. 

The lymphatics are arranged in a superficial and a deep set. The for- 
mer open, in general, into the superficicd inguinal glands; the latter into 
the deep inguinal glands. The superficial follow, in a general way, the 
course of the long saphenous vein; the deep accompany the deep blood- 
vessels, and in the leg enter the popliteal glands ; in the gluteal and ad- 
ductor region some enter the internal iliac glands. 

The superficial lymphatics of the lower part of the trunk also join 
the superficial inguinal glands. The superficial lymphatics of the penis 
enter the superior set of superficial inguinal glands ; the deep run under 
the pubic arch to join the internal iliac glands. The superficial lym- 
phatics of the scrotum join the superficial inguinal glands. In the 
female external genitalia a similar disposition obtains. 

The superficial inguinal glands, eight or ten, consist of a superior or 
oblique set in the line of Poupart's ligament, and an inferior or vertical 
set lying around the upper part of the saphenous vein. Efferent vessels 
join the deep inguinal and external iliac glands. 

The four or five popliteal glands surround the vessels, and receive the 
deep and some superficial absorbents of the leg. 



246 LYMPHATICS. 

The deep inguinal glands lie around the femoral vessels; one at the 
crural ring is constant. 

Describe the lymphatics and lymphatic glands of the pelvis and 
abdomen. 

They include the following : 

Six or more extern id iliac glands surround these vessels. 

Numerous internal iliac glands, and sacral glands on the face of the 
sacrum. 

The lymphatics of the bladder enter the internal iliac glands with the 
prostatic branches. 

The lymphatics of the uterus, with those of the vagina, to the internal 
iliac glands. 

The lymphatics of the rectum enter the sacral glands. 

The lumbar glands comprise a middle and two lateral groups. The 
former lie around the aorta and vena cava, the latter beneath the psoas. 
Most of the efferent vessels join to form, on each side, the lumbar lym- 
phatic trunk, which runs into beginning of thoracic duct. 

The lymphatics of the kidney, deep and superficial, join the middle 
lumbar set after receiving the suprarenal lymphatics and some from the 
ureter. 

The lymphatics from the testicles, superficial and deep, through the 
inguinal canal, in the cord, to join the lumbar glands. 

The deej) lymphatics of the abdominal icall receive others from the 
spinal canal and muscles, and join the lateral lumbar glands. At the 
upper part they enter the sternal glands. 

About one hundred and fifty mesenteric glands lie between the layers 
of the mesentery in the arterial arches and around the superior mesen- 
teric artery. 

The lactcals form one plexus beneath the mucous membrane and one 
in the muscular coat, and leave the intestine at the attachment of the 
mesentery to enter the mesenteric glands, and, emerging, join the efferent 
vessels from the cceliac glands and form a single trunk. This intestinal 
lymphatic trunk joins the thoracic duct. 

Sixteen to twenty cceliac glands, around the cceliac axis and adjacent 
aorta, receive the lymphatics from the stomach, spleen, pancreas, and a 
large part of the liver. 

The lymphatics of the stomach traverse the gastric glands at the 
greater and lesser curvature and join the cceliac glands. From the 
left end they join the splenic lymphatics. 

The lymphatics of the spleen, superficial and deep, enter the cceliac 
glands after receiving the pancreatic vessels. 

The lymphatics of the liver are superficial and deep. The superficial 
on the upper surface are arranged in four groups: (1) The mesial, from 
both lobes, run through the diaphragm to the anterior mediastinal glands ; 
(2) the lateral of each lobe to the cceliac glands ; (3) the posterior, through 



THE ABSORBENT SYSTEM. 247 

the diaphragm to the glands around the inferior vena cava; (4) an an- 
terior group joins those on the inferior surface. 

The superficial lymphatics on the lower surface run to the transverse 
fissure, for the most part, to join with the deep lymphatics. Some join 
the gastric lymphatics. 

The deep hepatic lymphatics accompany the portal and hepatic veins. 
The former join the other vessels from the under surface at the transverse 
fissure, and traverse some small hepatic glands to join the coeliac glands. 
Those accompanying the hepatic veins form five or six trunks piercing 
the diaphragm, and join the glands around the vena cava. 

Describe the lymphatic system of the thorax. 

Six to ten internal mammary or sternal glands along the course of the 



Along the line of the heads of the ribs, on each side of the spine, are 
the intercostal glands. They send vessels to both the thoracic and right 
lymphatic ducts. 

Several anterior mediastinal glands lie between the sternum and the 
pericardium. 

Eight or ten superior mediastinal or cai'diac, around the great vessels, 
receive the lymphatics of the heart and thymus gland. 

Numerous bronchial glands, between the bronchi and along their 
primary divisions, receive the lymphatics of the lung. They deepen 
in color as age advances. 

Ten or twelve posterior mediastinal, along the oesophagus and aorta. 

The deep lymphatics of the chest-wall are an anterior set, in the inter- 
costal spaces, joining the internal mammary glands, and a posterior or 
intercostal set, along with the intercostal vessels, joining the intercostal 
glands. 

The cardiac lymphatics run toward the base of the heart, and form a 
trunk on each side. Of these, the right enters a gland above the aortic 
arch ; the left, the glands behind that vessel. 

The pulmonary lymphatics, superficial and deep, end in the bronchial 
glands. 

The oesophageal lymphatics form a plexus between the muscular and 
mucous coats and join the posterior mediastinal glands. 
■ The thymic lymphatics enter the superior mediastinal glands. 

Describe the lymphatics of the upper limb. 

They consist of a superficial and a deep set, both converging to the 
axillary glands. The former have a somewhat similar distribution to 
that of the veins, some entering the infraclavicular glands ; the latter 
correspond to the deep blood-vessels, communicate with the superficial 
lymphatics near the wrist, traverse the glands around the brachial artery 
near the elbow, and end in the axillary. 



248 LYMPHATICS. 

Describe the axillary gtends. 

They are ten to twelve in number, and lie mostly along the axillary 
vessels, but some, the pectoral, subscapular, and infraclavicular, occupy 
the positions indicated by their names. The efferent vessels from all 
these glands run along the subclavian vein, and may unite into a single 
axillary lymphatic trunk. They finally reach the thoracic or right lym- 
phatic duct respectively, or they may enter the subclavian vein directly. 

The superficial lymphatics of the chest drain the lymph from the pec- 
toral muscles, skin, and mamma, and together with some superficial ab- 
dominal lymphatics, enter the axillary glands. Those from the back 
converge from all parts to reach the axillary glands. 

Describe the absorbent system of the head and neck. 

One or more suboccipital glands on the complexus send branches to 
the cervical glands. 

Several mastoid glands over the insertion of the sterno-mastoid. 

Some parotid glands, beneath the parotid fascia and imbedded in the 
gland, receive superficial temporal lymphatics, and send branches to the 
submaxillary and superficial cervical glands. 

The internal maxillary glands, deep beneath the ramus of the jaw, 
around the artery and side of the pharynx, with branches to the deep 
cervical glands. 

Eight or ten submaxillary glands beneath the base of the jaw drain 
the lymph from the floor of the mouth and the salivary glands and from 
the parotid lymphatic glands. The efferent vessels join the superficial 
and deep cervical glands. 

The superficial cervical glands, four to six, along the external jugular 
beneath the platysma, receive the auricular lymphatics, efferent trunks 
from the suboccipital, mastoid, and some from the parotid and submaxil- 
lary glands. The efferent vessels enter the inferior deep cervical glands. 

The deep cervical, twenty to thirty, consist of an upper and a lower 
set. The former run along the internal jugular vein ; the latter around 
the lower part of the vein and into the supraclavicular fossa, and join 
the superior mediastinal and axillary glands ; they receive afferent trunks 
from all the other cervical glands and the lymphatics of the lower part 
of the neck, and send out branches which unite into a jugular lymphatic 
trunk. This trunk then joins the thoracic or right lymphatic duct, or 
may open into a large vein. 

The lymphatics of the scalp join the suboccipital, mastoid, and parotid 
glands. 

The lymphatics of the face follow the course of the facial vein to the 
submaxillary glands, but there are others externally which join the parot- 
id glands. The deep lymphatics from the orbit) nasal cavity, palate. 
and cheek join the internal maxillary glands. 

The cranial lymphatics form a network in the pia mater, and run along 
the internal carotid, vertebral, and internal jugular veins to the deep 
cervical glands. 



THE SPINAL CORD. 249 

The Ungual lymphatics run with the ranine vein, traverse several lin- 
gual glands, and join the upper deep cervical glands. One or two join 
the submaxillary. 



NEUROLOGY. 

THE SPINAL CORD. 
What are the membranes of the spinal cord ? 

The spinal cord is enclosed by three membranes, the dura mater, 
arachnoid, and pia mater. 

Describe the dura mater. 

This is a loose fibrous envelope which is attached closely to the margin 
of the foramen magnum above, but only loosely to the circumference of 
the vertebral canal below. Its inner surface is covered by a layer of epi- 
thelium, and it presents on each side a series of double orifices for the 
exits of the anterior and posterior roots of the spinal nerves. The dura 
is prolonged on to these nerves as a tubular investment. 

Describe the arachnoid. 

The arachnoid is a very delicate membrane which invests the cord be- 
tween the dura and pia. It is continuous above with the cerebral arach- 
noid, and is connected by meshes of fibrous tissue with the pia, and to 
some extent also with the dura, from which it is separated by the sub- 
dural space. The subarachnoid space contains the subarachnoid fluid, 
which separates it from the pia mater. This space, by means of the 
foramen of Majendie, is continuous with the cavity of the ventricles of 
the brain. 

Describe the pia mater. 

The pia mater is closely connected to the cord, and sends a prolonga- 
tion down into the anterior, and a very delicate process into the posterior 
median fissure. It ensheathes the spinal nerves, and ends below in the 
filum terminale, which joins the dura at the upper limit of the sacral 
canal. 

Along the anterior median surface of the pia runs a prominent fibrous 
band, the linea splendens, and between the two nerve-roots on each side 
is a serrated band, the Ji'gamentimi denticulatum, the points of the serra- 
tions, about twenty on each side, being attached to the dura between the 
pairs of nerve-roots. 

Describe the spinal cord. 

It is about 18 inches long, weighs an ounce and a half, and occupies 



250 THE SPINAL CORD. 

about the upper two-third3 of the spinal canal — viz. from the foramen 
magnum to the upper border of the second lumbar vertebra. It ends in 
a narrow cord of gray matter which runs in the midst of the filum ter- 
niinale. 

What enlargements are found in the spinal cord? 

The spinal cord presents two enlargements — an upper or cervical, ex- 
tending from the third cervical to the first or second dorsal vertebra, and 
a lower or lumbar, from the tenth dorsal to about the first lumbar. 
These enlargements correspond to the origin of the nerves which supply 
the upper and lower extremities respectively. The surface of the cord 
presents several fissures, which will now be described. 

What are the fissures of the cord ? 

The anterior median fissure extends through about one-third the 
thickness of the cord, as far as the anterior white commissure, and con- 
tains a fold of the pia. 

The posterior median fissure extends about halfway through its sub- 
stance to reach the posterior or gray commissure. It is not a real fissure, 
being filled up by connective tissue. 

The antero-lateral fissure is merely the line of origin of the anterior 
nerve-roots, while the postero-lateral is in reality a groove, and runs along 
the line of origin of the posterior nerve-roots. 

Lastly, a slight groove marks off the jjosterior median column on either 
side of the posterior median fissure. 

How are the columns of the cord formed ? 

These fissures divide the cord into four columns on each side. 

The anterior column, between the anterior median and antero-lateral 
fissures, is continued above into the pyramid of the medulla. The lat- 
eral, between the antero- and postero-lateral fissures, runs up to become 
apparently the lateral column or tract of the medulla. The postenor 
column, between the postero-lateral and posterior median fissures, be- 
comes divided, by the slight groove above mentioned, into the postenor 
lateral and posterior median columns. In the medulla the former be- 
comes the funiculus cuneatus, the latter the funiculus gracilis. 

What is the structure of the cord? 

The spinal cord is composed of white matter externally and of gray 
matter within. The latter presents on section the appearance of two 
crescents, the horns looking outward, united across the median line by 
the gray commissure, which is placed nearer to the apices of the anterior 
than to those of the posterior cornua, The posterior cornua are long 
and narrower than the anterior, and extend almost to the surface of the 
cord at the postero-lateral fissure, where they give off the posterior nerve- 
roots. The anterior are blunt and do not reach the surface ; thus the 



THE SPINAL CORD. 251 

anterior roots pierce the white matter and emerge at the antero-lateral 

assure. The gray commissure is separated from the anterior median 
fissure by the anterior white commissure, but the posterior median fis- 
sure quite reaches it. 

Throughout the whole length of the cord in the gray matter runs a 
small centra] canal which opens above into the fourth ventricle and en- 
larges below, at its termination. It is lined by cylindrical epithelium. 

The white matter is composed of medullated nerve-fibres of varying 
calibre, held together by a delicate reticular connective tissue, the neur- 
oglia, containing numerous neuroglia-cells. _ This neuroglia sends in 
septa, along with which pass processes of pia mater, thus subdividing 
the columns into smaller tracts. 

Describe the anterior column. 

The anterior column is subdivided into the following : 
(1) On either side of the anterior median fissure the direct pyramidal 
tract, forming above the uncrossed portion of the pyramids of the me- 
dulla, and (2) the fundamental fasciculus. 

Describe the lateral column. 

The lateral column is subdivided into (1) the mixed lateral tract, next 
to the concavity of the gray substance ; (2) the anterior vadiadar zone, 
somewhat in front; (3) the direct cerebellar tract, behind peripherally; 
and (4) the crossed pyramided tract, lying internal to the latter. Of 
these the first and second join the lateral tract or column of the medulla, 
the third traverses it to reach the restiform body, and the fourth joins 
the pyramid of the opposite side, forming, with its fellow, the decussa- 
tion of the p3 T ramids. 

Describe the posterior column. 

The posterior column is marked off into (1) the column of Goll, or 
posterior median column, and (2) Burdaclis column, or the posterior 
lateral column. The first becomes the fasciculus gracilis; the second 
enters the medulla under its own name or as the funiculus cuneatus. 

Mention some points in the structure of the gray matter. 

The posterior cornu is constricted at its base (cervix cornu), and then 
expands {caput cornu) before narrowing to its extremity {apex cornu). 
Around the latter the neuroglia forms the substantia r/elatinosa. 

The gray matter of the cord consists of nerve-fibres, nerve-cells, and 
connective tissue {neuroglia). The nerve-cells are for the most part 
arranged in columns. Of these columns, one, at the inner side of the 
cervix cornu, is called the posterior vesicular column of Lockhart Clarke ; 
a second, at the concavity of the gray matter, the tractus intermedio- 
lateralis ; and a third is found along the anterior part of the anterior 
cornu. 



2^2 THE BRAIN OR ENCEPHALON. 

THE BRAIN OR ENCEPHALON. 

What is the encephalon? 

The encephalon or brain is that part of the cerebro-spinal axis which 
is contained in the cranium. It is composed of the cerebrum, cerebel- 
lum, pons Varolii, and medulla oblongata. 

What are the membranes of the brain ? 
They are the dura mater, pia mater, and arachnoid. 

Describe the dura mater. 

The dura is similar in structure to the dura of the cord, but differs 
from it in being closely attached to the cranial bones, forming, in fact, 
their inner periosteum. It is continuous with that of the cord at the 
foramen magnum, and with the external periosteum of the cranial bones 
by means of its prolongations into the many foramina. It sends in 
various processes to support and separate the different parts of the 
brain, and its layers separate to form the cranial sinuses. In the vicin- 
ity of the superior longitudinal sinus are to be found, on its outer sur- 
face, several glandule Pacchionii. They may also be seen on its inner 
surface and within the sinus, as well as on the pia mater. 

The processes include the falces cerebri et cerebelli and the tentorium 
cerebelli. 

The falx cerebri separates the cerebral hemispheres. In front it is 
narrow, becoming broader behind. Its upper convex margin is attached 
to the vault of the cranium from the crista galli in front to the internal 
occipital protuberance behind. Its lower margin is free and concave an- 
teriorly, while it is attached posteriorly to the upper surface of the ten- 
torium. Above it forms the superior, below, the inferior longitudinal 
sinus and part of the straight sinus. 

The falx cerebelU is triangular, and separates, inferiorly, the lateral 
cerebellar lobes. It is attached above to the middle of the posterior 
border of the tentorium, behind to the internal occipital crust, below 
the torcular Herophili, and to the foramen magnum, where it often 
divides into two parts, which are attached to its margins. 

The tentorium, covers the upper surface of the cerebellum. Its poste- 
rior border, where it is attached to the transverse ridges of the occipital 
bone, encloses the lateral sinuses; along the superior border of the 
petrous portion it forms the superior petrosal sinus, and at the junction 
of its upper surface with the falx cerebri is the straight sinus. Besides 
these points, it is attached to the anterior and posterior clinoid processes. 
Its anterior concave edge is marked by an oval opening for the crura 
cerebri. 

Describe the arachnoid and pia mater. 

The arachnoid is a similar membrane to that of the cord, and is sepa- 
rated, as in the cord, by the subarachnoid fluid from the pia. It does 



THE MEDULLA OBLONGATA. 253 

not dip into the sulci. In front it loaves a space between it and the pia 
mater, viz. along the pons and interpeduncular region, the anterior sub- 
arachnoidean space, and behind, between the medulla and the cerebellum, 

is a second interval called the posterior subarachnoidean space. Both are 
connected with the ventricles of the brain by the foramen of Magendie 
in the pia mater covering the fourth ventricle. 

The subarachnoid fluid is a clear alkaline fluid containing 1.5 per cent, 
of solids, animal and mineral. 

The pia mater is a very vascular, delicate membrane which dips into 
the sulci and forms the various choroid plexuses and also the velum of 
the third ventricle. The vessels of the brain run in the pia mater before 
entering the brain. 

Describe the medulla oblongata. 

It is a pyramidal body. 1 inch long, f inch wide, and •} inch thick. 
Its larger extremity is continuous with the pons ; its smaller extremity, 
directed downward and backward, blends with the spinal cord. The an- 
terior surface lies on the basilar groove of the occipital bone, and the 
posterior in the vallecula, between the cerebellar hemispheres. 

In front and behind it is marked by the continuation of the anterior 
and posterior median fissures of the cord, the former, with its process 
of pia mater, ending in a cul-de-sac just below the pons, the foramen 
caecum. The posterior expands into the fourth ventricle. 

Each lateral half of the medulla is divided into "columns." 

Describe each of these " columns." 

1. The 'pyramid. This contains internally the fibres of the crossed 
pyramidal tract from the lateral column of the opposite side of the cord ; 
externally the pyramid contains the direct pyramidal tract from the an- 
terior column of the cord of its own side. 

2. The lateral tract is the apparent continuation of the lateral column 
of the cord. It is very short, and lies immediately under the 

3. Olivary body. This is an oval mass of white matter enclosing the 
corpus clentatum, a gray nucleus which is hollowed out within and open 
at its upper part, admitting white fibres. Above and in front a groove 
separates it from the pons and pyramid. Crossing it are arched fibres 
which join the restiform body. 

4. The restiform body is apparently continuous with the posterior col- 
umns of the cord, and diverges above from its fellow to form the lateral 
walls of the lower part of the fourth ventricle. It passes to the cere- 
bellum, together with the direct cerebellar tract of the cord. 

Immediately below the restiform body from without inward are : 5, 
the funiculus of Rolando ; 6, the funiculus cuneatus ; and 7, the funicu- 
lus gracilis or the column of Goll continued up. Its enlarged extremity, 
the processus clavatus, lies just under the restiform body. The angle 
of divergence from its fellow of the opposite side is called the calamus 
scriptorius. 



254 THE BRAIN OR ENCEPHALON. 

Mention some points in regard to the deep structure of the 
medulla. 
Numerous white fibres run in the median line, forming the so-called 
septum of the medulla. Some of these fibres emerge from the ant. med. 
fissure and cross the olivary body as the arciform fibres, which join the 
restiform body. Must of the remaining white fibres are the continuation 
upward of the fundamental fasciculus, the mixed lateral tract, and the 
anterior radicular zone. (See Columns of the Cord.) The crescentic 
arrangement of the gray matter which obtains in the cord is lost in the 
medulla. The caput cornu enlarges and appears close to the surface as 
the funiculus of Rolando, which swells above into the tubercle of Ro- 
lando. The gray matter of the base of the posterior cornu forms the 
nucleus gracilis in the funiculus gracilis and the nucleus cuneatus in the 
funiculus cuneatus. A part of the base of the anterior cornu forms the 
eminence of the funiculus teres, in which is the hypoglossal nucleus, 
while that part of the cornu which is left is known as the formatio 
reticularis. 

Describe the pons Varolii (tuber annulare). 

This part of the brain serves to connect its various divisions. Situated 
between the cerebellar hemispheres, it forms on each side the middle pe- 
duncles of the cerebellum. Its dorsal surface forms the upper part of 
the floor of the fourth ventricle. The ventral surface rests on the sphe- 
noid and basilar groove of the occipital bone, and lodges the basilar 
artery in a median furrow, its branches running in smaller lateral de- 
pressions. The pons is arched above, below, and ventrally. 

Describe the structure of the pons. 

It is made up of nerve-fibres and gray matter. There are two sets of 
fibres, transverse and longitudinal, and each set has superficial and deep 
fibres. These four layers alternate with each other from below as fol- 
lows : 1 , superficial transverse fibres ; 2, superficial longitudinal fibres ; 
3, deep transverse fibres ; 4, deep longitudinal fibres. The first and 
third lawyers are prolonged into the middle peduncles of the cerebellum. 
The second layer is the prolongation upward of the fibres of the pyra- 
mids of the medulla. The fourth layer (immediately below the floor of 
the fourth ventricle) is the upward prolongation of the fibres in the 
11 deep structure" of the medulla. (See above.) 

The gray matter occurs chiefly as: 1, small points (nuclei pontis) scat- 
tered amongst the fibres ; 2, the superior olivary nucleus, situated behind 
the third layer of white fibres {trapezium). 

Describe the cerebrum. 

The cerebrum is the largest part of the brain, and is composed of two 
symmetrical halves separated by the great longitudinal fissure. As a 
whole it is flattened below, convex above, broader behind than in front, 
and presents over its entire surface convoluted eminences, the gyri or 



LOBES AND FISSURES OF THE CEREBRUM. 255 

convolutions, separated by depressions, the sulci and fissures. _ The two 
hemispheres are connected by a great transverse white commissure, the 
corpus callosum. 

1 he outer surface, including the gyri, is composed of gray matter, the 
cortical substance, while the interior is of white matter. The cortical 
layer is composed of alternate strata of white and gray matter. 

The sulci vary from J an inch to 1 inch in depth. Several well-marked 
sulci divide the surface into five lobes. They are the interlobar sulci or 
fissures, and include the fissure of Sylvius, fissure of Rolando, and the 
parietooccipital fissure. 

Describe the interlobar sulci. 

The fissure of Sylvius runs outward from the anterior perforated space, 
and divides, on the outer side of the hemisphere, into an ascending limb, 
which runs upward and forward for about an inch, and a horizontal limb, 
which runs back between the parietal and temporo-sphenoidal lobes. 

The fissure of Rolando (central sulcus), from its commencement (£ inch 
behind the mid-point between the glabella and external occipital protu- 
berance), runs downward and forward, to end a little behind and above 
the bifurcation of the Sylvian fissure. 

The parieto-occipital fissure commences at a point midway between the 
posterior extremity of the brain and the fissure of Rolando, and runs 
downward and forward on the mesial surface of the hemisphere nearly 
as far as the corpus callosum, and runs similarly also for nearly an inch 
on the convex surface. The first part is well marked, and is called the 
internal, the second the external, parieto-occipital fissure. 

Describe the lobes and fissures on the external surface of the 
cerebrum. 

The frontal lobe lies in front of the fissure of Rolando, and above 
and in front of the ascending limb of the Sylvian fissure. It rests on 
the orbital plate below. 

The precentral fissure runs parallel with the lower part of the fissure 
of Rolando, marking off the ascending frontal convolution, and the part 
in front of it is divided by the superior and inferior frontal sulci, both 
running antero-posteriorly, into the superior or first, middle or second, 
and inferior or third frontal convolutions. The last is also called Broca's 
convolution. The under surface of the frontal lobe is grooved for the 
olfactory tract, a sulcus also separating the lower part of the first frontal 
convolution internally from the continuation of the second and third 
externally, the latter two being also separated by a sulcus. These gyri 
are called respectively the internal, middle, and posterior orbital con- 
volutions. 

The parietal lobe is bounded in front by the fissure of Rolando, be- 
hind by the parieto-occipital, and below by the horizontalpart of the 
Sylvian fissure, which separates it from the temporo-sphenoidal lobe. 

The intraparietal fissure runs up, at first parallel to the fissure of 



256 THE BRAIN OR ENCEPHALON. 

Rolando, then turns backward, separating the superior and inferior 
parietal lobules. It marks off between it and the fissure of Rolando 
the ascending parietal convolution. The superior parietal convolution 
or lobule is continuous in front with the ascending parietal, and the in- 
ferior parietal lobule is subdivided by a vertical sulcus into the supra- 
marginal gyrus in front and the angular gyrus behind. The former is 
continuous in front with the superior temporo-sphenoidal, and the latter, 
behind, with the middle temporo-sphenoidal gyrus. 

The occipital lobe is partly separated in front from the parietal by 
the parietooccipital fissure, and forms, behind, the posterior extremity 
of the hemisphere. It is divided by the superior and middle occipital 
fissures into the superior, middle, and inferior occipital convolutions. 
These are connected by the annectant convolutions with the adjacent 
gyri as follows: the first annectant convolution connects the superior 
occipital with the superior parietal ; the second connects the middle 
occipital with the angular ; the third connects the middle occipital with 
the middle temporo-sphenoidal ; and the fourth joins the inferior occip- 
ital and inferior temporo-sphenoidal convolutions. The inferior occipital 
fissure, at the side of the lobe, separates the inferior convolution from the 
occipitotemporal. 

The temporo-sphenoidal lobe is bounded above and in front by 
the beginning of the fissure of Sylvius and its horizontal limb; is con- 
tinuous behind with the occipital, and above with the parietal lobe. It 
lies in the middle fossa of the skull. The superior temporo-sphenoidal 
sulcus, with the middle and inferior, divides it into three convolutions, 
named, from above downward, the first, second, and third temporo- 
sphenoidal. 

The central lobe (island of Reil or insula) is triangular, and con- 
sists of five or six convolutions, the gyri operti. It lies in the fissure of 
Sylvius and beneath the inferior extremities of the ascending frontal 
and ascending parietal convolutions, which, joined by the inferior frontal, 
form the operculum. In front and externally a deep sulcus separates 
it from the orbital and frontal convolutions. 

Describe the mesial and tentorial surfaces of the hemisphere. 

The calcarine fissure commences at the back of the hemisphere by 
two branches, and as it runs forward is joined by the internal parieto- 
occipital fissure, ending near the back part of the gyrus fornicatus. It 
forms the calcar avis or hippocampus minor in the posterior horn of the 
lateral ventricle. 

The callosn-marginal fissure runs from under the front of the corpus 
callosum, between the gyrus fornicatus and the upper margin of the 
hemisphere, then ascends to end in the upper part of the fissure of 
Rolando or close behind it. 

The hippocampal or dentate fissure runs from within the back part of 
the gyrus fornicatus to the hook of the uncinate gyrus. It forms by its 
projection into the ventricle the hippocampus major. 



THE I'NDEi; SURFACE OF THE ENCEPHALON. 257 

The internal parietooccipital fissure runs downward and forward to 
join the calcarine fissure. 

The collateral or occipito-ternporal fissure separates the superior and 
interior occipito-ternporal convolutions, and forms the eminentia col- 
la t oralis. 

The cuneate or occipital lobule lies between the parietooccipital and 
calcarine fissures. 

The precuneus (quadrate lobule) lies between the parietooccipital and 
the termination of the calloso-marginal fissure. 

The marginal convolution is the inner aspect of the first frontal, and 
runs along the margin of the longitudinal fissure from the anterior per- 
forated space to the calloso-marginal fissure. 

The gyrus fornicatus runs from the anterior perforated space around 
the genu of the corpus callosum, then back along its upper surface, 
around the posterior extremity, and lastly, as the gyrus hippocampi, runs 
forward to end in the uncinate gyrus. It is bounded above by the 
calloso-marginal fissure. 

The uncinate gyrus is the terminal part of the preceding. It extends 
to the fissure of Sylvius. In front it bends back in the form of a hook, 
the uncus. The under and inner surface of the temporo-sphenoidal lobe 
presents two convolutions separated by the collateral fissure. They are 
the lateral and median occipito-ternporal, or, respectively, the fusiform 
and lingual convolutions. 

Describe the under surface of the cerebrum. 

It presents three lobes: the anterior, composed of the under surface 
of the frontal, resting on the orbital plate ; a middle, composed of the 
parietal and temporo-sphenoidal ; and a posterior, the occipital lobe. 
The middle lies in the middle fossa, the posterior on the upper surface 
of the tentorium cerebelli. 

From before backward the following parts come into view : longitu- 
dinal fissure, corpus callosum, lamina cinerea, olfactory bulb and tract, 
fissure of Sylvius, anterior perforated space, optic commissure, tuber 
cinereum, infundibulum, pituitary body, corpora albicantia, posterior 
perforated space, crura cerebri. 

Describe each of these parts. 

The great longitudinal fissure completely separates the anterior and 
posterior lobes, but is interrupted between these two points by the 
corpus callosum. 

The corpus callosum is placed nearer the front than the back of the 
hemispheres, being convex from before backward above, concave below ; 
the fibres run transversely, but along the middle line is a longitudinal 
raphe with a white band on each side, the mesial longitudinal strice, and 
near the margin some lateral longitudinal strice. 

The lamina cinerea is a thin layer of gray matter lying between the 
chiasma and the corpus callosum, and continuous with the gray matter 
17— A. 



258 THE BRAIN OB ENCEPHALON. 

of the anterior perforated space on each side. It forms part of the 
floor and anterior boundary of the third ventricle. 

The olfactory tract runs in a groove close to the great longitudinal 
fissure on the under surface of the frontal, and ends in an enlarge- 
ment, the bulb, from which the olfactory nerves descend through the 
cribriform plate. Behind, the tract divides into two roots. The outer 
runs back along the margin of the anterior perforated space to the Syl- 
vian fissure ; the inner to the longitudinal fissure. The triangular space 
between the two roots is occupied by gray matter forming part of the 
tuber olfactorium, which lies in a depression on the frontal lobe, and is 
composed internally of white matter. 

The fissure of Sylvius lodges the middle cerebral artery. At its inner 
part is the fasciculus unciformis, connecting the frontal and temporo- 
sphenoidal lobes. 

The anterior perforated space is a triangular depression at the inner 
side of the Sylvian fissure, of a grayish color, and is pierced by many 
small vessels passing to the corpus striatum, under which it lies. 

The optic commissure or chiasma (see Optic Nerve) is formed by the 
union of the two optic tracts. It lies below the lamina cinerea and in 
front of the tuber cinereum. 

Between the optic tracts and the crura cerebri is a diamond-shaped 
area, the interpeduncular space. This space includes the tuber cine- 
reum, infundibulum, pituitary body, corpora albicantia, and the poste- 
rior perforated space. 

The tuber cinereum is an elevation of gray matter between the optic 
tracts and corpora albicantia, and forms part of the floor of the third 
ventricle. From its under surface the infundibulum runs down to the 
pituitary body. The former is hollow and of a conical form, its cavity 
communicating with the third ventricle. 

The pituitary body, or hypophysis cerebri, is a reddish-gray mass occu- 
pying the sella turcica. Its weight is from 4 to 10 grains. It consists of 
two lobes, the anterior and larger of which encloses the posterior. The 
former is of a yellowish-gray color ; the latter in foetal life contains an 
aperture which communicates with the infundibulum. 

The corpora albicantia are two bodies placed behind the tuber cine- 
reum. They are composed of white matter, are about the size of a pea, 
and contain each a gray nucleus which is connected with its fellow across 
the median line. Each is formed by the corresponding anterior pillar of 
the fornix. 

The posterior perforated space forms part of the posterior portion of 
the floor of the third ventricle, and is pierced by small vessels for the 
optic thalami. It occupies the interval between the corpora albicantia. 
the pons, and the crura cerebri. 

The crura cerebri are broader in front than behind and less than 1 
inch in length. They run from the upper border of the pons to the 
hemispheres of the cerebrum, under the optic tracts, which cross them. 



Tin-: LATERAL VENTRICLES. 259 

The fourth nerve crosses the outer side, and the third issues from the 
inner side of each. 

Each cms is composed of two parts separated by gray matter, the 
locus niger. The ventral part, or crusta^ is a continuation of the pyram- 
ided fibres from the medulla and pons, while the dorsal part, or teg- 
mentum, is the continuation of the deep longitudinal fibres of the pons. 
The crusts of the two sides are entirely separate, but the tegmenta are 
connected at the median line. 

Describe the parts seen on two horizontal sections of the cere- 
brum. 

A section of the hemispheres about 2 inch above the corpus callosum 
brings into view the white matter constituting the centrum ovale minus. 
This is dotted with the puncta vasculosa, due to the divided blood-ves- 
sels. A section at the level of the corpus callosum is called the centrum 
ovale majus of Vieussens. 

The anterior part of the corpus callosum forms in front a bend, the 
genu, and this extends back along the base of the brain up to the lamina 
cinerea as the rostrum. Here it sends off the peduncles of the corpus 
callosum. Behind it forms a thick border, the splenium or pad. The 
under surface of the corpus callosum is connected behind with the fornix 
and for the rest of its extent with the septum lucidum. It forms the 
roof of the lateral ventricles. 

Describe the lateral ventricles. 

These serous cavities have a thin lining membrane covered by a layer 
of epithelium cells (ependyma) which secretes a serous fluid. They are 
contained one in each hemisphere, separated by the septum lucidum, and 
each is divided into a body and three cornua, an anterior, posterior, and 
middle. The foramen of Monro connects them with the third ventricle. 

The central cavity or body is roofed by the corpus callosum, and in 
the floor, from without inward, are found the caudate nucleus of the 
corpus striatum, taenia semicircularis, part of the optic thalamus, cho- 
roid plexus, and part of the fornix. 

The anterior cornu projects into the anterior lobe and runs outward 
round the nucleus caudatus. Above and in front of it is the corpus 
callosum. 

The posterior cornu, or digital cavity, runs back into the posterior 
lobe, its direction being backward, outward, and lastly inward. Its floor 
presents the eminence of the hippocampus minor or calcar avis. At the 
junction of the posterior and middle cornua is the eminentia coUateralis 
or pes accessorius. 

The middle or descending cornu curves round the back of the optic 
thalamus, descending at first backward and outward. It then runs 
downward, forward, and lastly inward. In its floor are the hippocam- 
pus major and pes hippocampi, corpus fimbriatum, and choroid plexus ; 



260 THE BRAIN OR ENCEPHALON. 

the fascia dentata lies within the hippocampal or dentate fissure, and the 
transverse fissure runs along the inner side of the cornu. 

Describe these parts in detail. 

The corpus striatum is a mass of gray matter, and consists of an 
extraventricular portion imbedded in the hemisphere and called the len- 
ticular nucleus, and an intraventricular part in the body and anterior 
cornu, the nucleus caudatus. 

The caudate nucleus is pyrifonn, projecting into the body and anterior 
cornu by its broad end, and by its smaller end into the roof of the mid- 
dle cornu nearly to its tip. 

The lenticular nucleus is divided into three zones, visible on transverse 
vertical section. It is separated from the caudate nucleus by the internal 
capsule, and the external capsule separates it from the clauatrum. This 
nucleus and the caudate are joined together in front, and, behind, the 
lenticular is continuous with the gray matter of the anterior perforated 
space. 

The claustrum is a gray lamina marked externally by ridges and fur- 
rows corresponding to the gyri and sulci of the island of Reil. 

The nucleus amygdalae, is a small, yellowish-gray mass projecting into 
the apex of the middle cornu, and continuous with the cortical part of 
the apex of the temporo-sphenoidal lobe. 

The taenia semicircularis lies in a groove between the caudate nu- 
cleus and the optic thalamus. In front it joins the anterior pillar of the 
fornix ; behind it enters the nucleus amygdalae. Beneath it is the vena 
corporis striati. 

The choroid plexus is a very vascular fringe covered with epithe- 
lium continuous with that of the ependyma, and forms the border of 
the velum interposition. It extends from the foramen of Monro, where 
it is continuous with the other, across the floor of the body of the ven- 
tricle and into the middle cornu. 

The corpus fimbriatum is the narrow band of white matter on the 
hippocampus major into which is prolonged the posterior pillar of the 
fornix. 

The hippocampus major is a curved white prominence in the floor 
of the middle horn. Its lower part presents the appearance of a paw 
from its grooves and eminences, hence called the pes hippocampi The 
hippocampus major is caused by the dentate fissure, and the gray matter 
contained in this fissure (dentate convolution) projects as a free margin — 
the fascia dentata. 

The eminentia collateralis (pes accessorius) is formed by the col- 
lateral fissure (occipitotemporal). 

The great transverse fissure of Bichat, separating the cerebrum 
and cerebellum, lies between the fornix and the splenium of the corpus 
callosum above and the corpora quadrigemina below; laterally, it lies 
between the back part of the optic thalamus below and the corpus fim- 
briatum and fascia dentata above. 



THE OPTIC TH A LA MI. 261 

The septum lucidum separates the lateral ventricles. It is com- 
posed of two layers, a small space containing fluid being left between 
them called the fifth ventricle. It is attached above to the corpus cal- 
losum, below to the anterior part of the fornix and the reflected portion 
of the corpus callosum. 

The fornix is an arched longitudinal commissure of white matter be- 
low 7 the corpus callosum. its lateral margins forming part of the floor of 
the body of the lateral ventricles. In front its two lateral halves are 
divergent, and form the anterior pillars; behind they diverge into the 
two poster ior pillars ; the central part is the body. The body is trian- 
gular, attached above to the corpus callosum and septum lucidum ; be- 
low the velum interpositum separates it from the third ventricle and 
optic thalami. On each side project the choroid plexuses. 

The anterior pillars descend through the gray matter on the sides of 
the third ventricle and form the anterior boundaries of the foramen of 
Monro. _ Then they emerge at the base of the brain to form the corpora 
albicantia, from which each pillar turns upward and ends in the cor- 
responding optic thalamus. In their course each communicates with the 
peduncle of the pineal gland and the taenia semicircularis. 

The posterior pillars are connected with the corpus callosum, then 
enter the descending cornua, and are partly prolonged into the upper 
surface of hippocampus major and partly into the corpus fimbriatum. 

The foramen of Monro is a foramen connecting each lateral ven- 
tricle with the anterior part of the third. In front it is bounded by the 
anterior pillar of the fornix ; behind, by the anterior part of the optic 
thalamus ; above, by the anterior extremity of the body of the fornix. 

What is the velum interpositum? 

The velum interpositum is a process of the pia mater which oc- 
cupies the great transverse fissure, and hence separates the fornix from 
the third ventricle. In front it sends a process through the foramen of 
Monro to each lateral ventricle. From its under surface it supplies the 
two vascular processes which form the choroid plexuses of the third 
ventricle, and on each side the choroid plexuses of the lateral ventricles 
are found. 

What are the optic thalami? 

The optic thalami are two masses composed externally of white, 
internally of gray matter, and rest upon the tegmentum of the crura. 
The fibres of the crusta, forming the internal capsule, separate the outer 
surface of each from the lenticular nucleus of the corpus striatum. The 
inner surface of each forms the lateral boundaries of the third ventricle ; 
its upper surface is grooved, and presents in front the projection of the 
anterior tubercle. Part of the under surface forms part of the roof of 
the descending cornu ; the anterior extremity is the hinder boundary of 
the foramen of Monro. 



262 THE BRAIN OR ENCEPHALON. 

Describe the third ventricle. 

This is the expanded interval into which the Sylvian aqueduct opens, 
and which lies between the optic thalanii. The velum intcrpositum, with 
the choroid plexuses, connected on each side with the peduncles of the 
pineal gland, forms its roof, together with the posterior commissure. 
Its floor presents the lamina cinerea, tuber cinereum, infundibulum, cor- 
pora albicantia, posterior perforated space, and tegmentum of crura. 
Ib front it is bounded by the anterior commissure and the lamina cine- 
rea. Behind is the opening of the aqueduct of Sylvius. 

In its cavity are three commissures: the anterior, in front of the ante- 
rior pillars of the fornix, piercing on each side the corpus striatum ; the 
middle or soft, of gray matter, connecting the thalami; and the poste- 
rior, also connecting the optic thalanii behind, and lying in front of and 
beneath the jyiiiad gland. 

In front are the two openings, one on each side, of the foramen of 
Monro. 

Describe the parts in relation with the Sylvian aqueduct. 

The pineal gland (epiphysis cerebri) is a small reddish body placed 
between and upon the upper pair of corpora quadrigemina. It has two 
peduncles, which run along the junction of the inner and upper surfaces 
of the optic thalami to join the anterior pillars of the fornix. Just be- 
fore entering the pineal gland they are joined together, the connecting 
band joining, in front, the posterior commissure. This gland is a collec- 
tion of follicles containing a clear, viscid matter and the brain sand 
(acervulus cerebri), a kind of phosphatic calculi. 

The corpora quadrigemina are rounded masses of gray matter 
thinly covered with white, arranged as an upper and a lower pair. They 
lie above the Sylvian aqueduct and behind the posterior commissure, and 
upon the terminations of the superior peduncles of the cerebellum of 
each side. . The anterior or upper pair are the larger. On each side 
they are connected with the thalami and optic tracts by white bands, 
the brachia, anterior and posterior. 

The geniculate bodies lie against the under and back part of each 
thalamus, external to the corpora quadrigemina. They are named ex- 
ternal and internal, and are separated by one of the roots of the optic 
tract. 

Describe the cerebellum. 

The cerebellum is that part of the cerebro-spinal axis which is_ con- 
tained in the inferior occipital fossa?. Its weight is about one-eighth 
that of the cerebrum, being proportionately large in the infant. It con- 
sists of gray matter externally, white internally. 

Describe its upper surface. 

The upper surface presents a median elevation, the superior vermi- 
form process, which connects together the upper surfaces of the two 






THE CEREBELLUM. 263 

hemispheres of the organ. In front and behind the hemispheres are 
separated by two notches, the incisura cerebelli anterior and 'posterior 
respectively. 

Describe the superior vermiform process. 

It is divided into four lobes, the lingula, the lobulus centralis, mon- 
ticulus cerebelli) and commissura simplex, or folium cacuininis. The first 
is on the valve of Vieussens, the second is in the anterior, the last in 
the posterior incisura, and the third is the most prominent part of the 
process. 

Describe the under surface of the cerebellum. 

The under surfaces of the hemispheres are separated by the vallecula, 
in which is found the inferior vermiform process, on which from behind 
forward are found the following: commissura brev is or tuber valvulae, 
pyramid, uvula, lying between the amygdalae and joined w r ith them by 
the furrowed band and nodule, with the inferior medullary velum on 
each side. 

Mention the lobes of the cerebellar hemispheres. 

Each hemisphere presents numerous deep and curved fissures very 
close together. The largest, the great horizontal fissure, runs from the 
point of emergence of the peduncles on each side, to end at the same 
point as its opposite fellow in the incisura posterior. Secondary fissures 
proceed from it in various directions. The great fissure divides each 
hemisphere into an upper and a lower part, and the secondary fissures 
divide them into lobes. These lobes are the following: 

Upper surface, anterior or square lobe ; posterior or semilunar lobe. 

Under surface, from before backward, the flocculus or pneumogastric 
lobule ; tonsil or amygdala ; digastric or biventral lobe ; slender lobe 
(gracilis) ; and the inferior posterior or postero-inferior lobe. 

Name and describe the peduncles of the cerebellum. 

They connect the cerebellum with the other parts of the encepha- 
lon. They are the superior, middle, and inferior peduncles of the cere- 
bellum. 

The first run to and beneath the corpora quadrigemina, and form part 
of the roof of the fourth ventricle, the valve of Vieussens lying between 
the two ; the second are the prolongation of the transverse fibres of the 
pons ; and the third are simply the upper part of the restiform bodies. 
They are all of white matter. 

What is the arbor vitae? 

It is the name given to the arrangement of the white matter of the 
cerebellum as seen on a median section. (See Fig. 14.) 

Describe the fourth ventricle. 

The fourth ventricle is placed between the medulla and pons in front 
and the cerebellum behind. It is diamond-shaped, the lower triangle 



264 



THE BRAIN OR ENCEPHALON, 
Fig. 14. 




Right half of the Encephalic Peduncle and Cerebellum as seen from the inside of a 
median section (Allen Thompson, after Reichert) : Pr, pons Varolii divided in the 
middle; m, medulla oblongata; c, central canal, divided longitudinally, with gray 
substance surrounding it; V 4 , middle of the fourth ventricle. In the cerebel- 
lum, nv, stem of white substance in the centre of the middle lobe of the cerebellum, 
ramifying into the arbor vitae; sv, superior vermiform process or upper portion of 
the middle lobe; sc, single folium (folium cacuminis). which passes across the pos- 
tero-superior lobes; c', the tuber valvule; p, pyramid; u, uvula ; n, nodule; 1 to 2, 
laminae of the monticulus cerebelli ; between V± and 1 are seen the lingula and cen- 
tral lobe in section; 3, postero-inferior lobe; -globulus gracilis; 5, biveutral lobe; 
6, amygdaloid lobe. II, right optic nerve; behind it the optic commissure divided; 
III, right third nerve; VI, sixth nerve; F 3 third ventricle; Th, back part of the 
thalamus opticus; //, section of the pituitary body; p, pineal gland: below its stalk 
is the posterior commissure; ca, anterior commissure divided, and behind it the 
divided anterior pillar of the fornix ; /c, lamina cinerea; i, infundibulum (cavity); 
tc, tuber cinereum ; behind it the corpus albicans ; /, mark of the anterior pillar of 
the fornix descending in the wall of the third ventricle; cm, commissura mollis; 
sp, stria pinealis or peduncle of pineal gland ; Q, corpora quadrigemina ; as, aqueduct 
of Sylvius near the fourth ventricle ; cr, crus cerebri. 



being bounded laterally by the davae of the funiculi graciles, the cuneate 
fasciculi, and the restiform bodies ; the upper by the sujurior jicd uncles 
of the cerebellum. Below it is continuous with the central canal of the 
cord ; above, with the Sylvian aqueduct. Laterally it projects, as the 



THE FOURTB VENTRICLE. 265 

lateral recesses, to the point of contact of the medulla and cerebellum, 
this being its widest part. The lower pointed part of the ventricle is 
called the columns scriptorius. 

The roof of the lower triangle is formed by a layer of epithelium cover- 
ing the under surface of the pia mater; that of the upper triangle is 
formed by the valve of Vieussens, together with the superior peduncles, 
in the upper part. The valve of Vieussens is streaked transversely by 
several laminae of gray matter separated by grooves, forming the lingula, 
which is a part of the superior vermiform process of the cerebellum. 

Describe the valve of Vieussens. 

The valve of Vieussens, or the superior medullary velum, is a white 
lamina between the superior peduncles of the cerebellum. Its upper 
part presents a ridge, the frenulum, on each side of which is the fourth 
nerve, joined by a transverse band with the opposite nerve. 

Describe the floor of the fourth ventricle and accessory struc- 
tures. 

The epithelium forming the roof of the lower triangle is continuous with 
that covering the floor, and is thickened by some white matter, which runs 
for some distance along the edge of the lateral boundary, from the lateral 
recess above, nearly to the calamus scriptorius below. This constitutes 
the taenia or ligula. The epithelium is also thickened over the point of 
the calamus, and is here called the obex. The two choroid plexuses of 
the fourth ventricle depend from the roof, covered by epithelium. They 
send processes into the lateral recesses, around which part of the ligula 
is reflected, forming the cornucopia. The floor, medullary portion, pre- 
sents several white lines, the strice acoustical, which run outward from 
the median line across the restiform body to the auditory nerve. The 
floor presents also a mesial groove, on each side of which, below the striae 
acousticae, toward which the apex is turned, is a small triangular depres- 
sion, the inferior fovea. Its base sends off a groove from each angle, 
the inner of which runs toward the point of the calamus scriptorius, 
marking off between it and the median groove, the prominent lower por- 
tion of the fasciculus teres, triangular in shape with its base toward the 
striae. The outer runs outward to the lateral boundary of the ventricle, 
and bounds a third triangular space with its base upward, ending near 
the striae in the acoustic tubercle. 

Between the two grooves just mentioned is a dark, somewhat trian- 
gular space, the ala cinerea, its narrower part at the inferior fovea, its 
broader side downward, forming the eminentia cinerea. Ventrally, this 
space practically includes the nuclei of the ninth, tenth, and eleventh 
nerves. 

The upper part of the floor of the fourth ventricle presents, just above 
the inferior fovea on each side, a somewhat similar depression, the 
superior fovea. Between it and the mesial groove is the upper part of 
the fasciculus teres, and running from it toward the iter above is a groove, 



26Q CRANIAL NERVES. 

the locus ca ruleus. The color of the latter is due to a line of pigmented 
nerve-cells forming the substantia ferruginea. 

In the floor of the fourth ventricle arc also found the nuclei from which 
arise the fifth nerve, the seventh, eighth, and sixth. That for the fifth, 
its motor portion, lies below the lateral angle, and its sensory portion, 
more extensive, lies external to the latter ; that for the seventh behind 
the superior olivary nucleus of the pons ; that for the sixth, in a column 
of multipolar cells in the fasciculus teres, above the stride acoustics ; 
and for the eighth the nuclei lie under the acoustic tubercle and striae. 
The nuclei of the third and fourth nerves are in the floor of the aqueduct 
of Sylvius, and that of the twelfth is in the fasciculus teres below the 
striae acousticae. 

CRANIAL NERVES. 

How many cranial nerves are there ? What are their names ? 

The cranial nerves consist of twelve pairs, as follows : 

1st pair, Olfactory; 7th pair, Facial, portio dura; 

2d pair. Optic ; 8th pair, Auditory, portio mollis ; 

3d pair, Motor oculi ; 9th pair, Glossopharyngeal ; 

4th pair, Pathetic; 10th pair, Pneumogastric ; 

5th pair, Trifacial ; 1 1 th pair, Spinal accessory ; 

6th pair, Abducens; 12th pair, Hypoglossal. 

What are the origins of the cranial nerves ? 

These nerves have each a superficial and a deep origin. The former 
corresponds to its point of attachment at the surface of the brain ; the 
latter to certain nuclei or collections of nerve-cells in the floor of the 
fourth ventricle and Sylvian aqueduct. 

Describe the olfactory nerves. 

The olfactory nerves, twenty on each side, descend from the under 
surface of the olfactory bulb through the cribriform plate to the nose. 
Internally they groove the vertical plate of the ethmoid ; externally, the 
inner surface of the lateral mass. They are all non-medullated nerves. 

Describe the optic nerves. 

The optic nerves of the two sides meet and partially decussate at the 
commissure or chiasma, back of which they enter the brain as the optic 
tracts. Each tract arises from the optic thalamus, corpora geniculata, 
and the superior corpus quadrigeminum as a flat band. This flattened 
band then crosses the crus cerebri, and, becoming rounded in form, is 
adherent to the tuber cinereum and lamina cinerea. 

The commissure lies on the olivary eminence of the sphenoid bone, and 
in it most of the fibres decussate. The outer, however, are prolonged 
into the nerve of the same side. From the commissure each optic nerve 
runs through the foramen opticum, ensheathed by the dura mater and 



THE FIFTH NERVE. 207 

arachnoid, and pierces the eyeball just inside Its centre, and, after run- 
ning through the sclerotic and choroid, expands to form the retina. 

Describe the motor oculi. 
The motor oculi arises superficially from the cms anterior to the 

§ons, its deep origin being a gray nucleus in the floor of the aqueduct of 
ylvins. It runs to the outer side of the posterior clinoid process, enters 
the cavernous sinus, runs above the other nerves in its outer wall, and 
divides into tiro branches, which enter the orbit between the two heads 
of the external rectus. It is joined in the sinus by sympathetic fila- 
ments. The superior branch crosses the optic nerve to supply the superior 
rectus and levator palpebrce. The inferior divides into three parts — one 
for the inferior oblique, one to the inner and one to the lower rectus. 
The first supplies the motor root of the lenticular ganglion. 

Describe the pathetic. 

The pathetic nerve has an apparent origin from the upper side of 
the valve of Vieussens, and a deep from the floor of the aqueduct of 
Sylvius. The two nerves communicate by a transverse band on the 
valve of Vieussens. The nerve pierces the dura after crossing over the 
crus, enters the cavernous sinus, in whose outer wall it lies between the 
ophthalmic and third nerves, then crosses the latter to enter the orbit 
through the sphenoidal fissure above the external rectus, and enters the 
superior oblique after crossing over the levator palpebrae. It receives 
sympathetic filaments in the sinus, and sends a recurrent branch into the 
tentorium. 

Describe the fifth nerve. 

The fifth or trifacial is the largest of all the cranial nerves, and arises 
by two roots, a motor and a sensory. The former is small, and the latter 
has the Gasserian ganglion upon it. Both arise from the side of the 
pons superficially, the smaller root above the larger, some transverse 
fibres of the pons separating the two. This nerve confers both motion 
and sensation. At the apex of the petrous portion of the temporal the 
large root forms the Gasserian ganglion ; the smaller does not join in the 
ganglion, but runs below it to join, just below the foramen ovale, the 
lowest trunk proceeding from the ganglion. 

Describe the Gasserian ganglion. 

The Gasserian ganglion lies in a hollow near the apex of the petrous 
portion of the temporal, the large superficial petrosal nerve, and the 
motor root lying below it. It receives branches from the carotid plexus. 
Small twigs pass to the dura mater. This ganglion sends off three large 
branches — viz. the ophthalmic, superior maxillary, and inferior maxillary. 

The first two confer sensation, the third motion and sensation. 

Describe the ophthalmic nerve. 

The ophthalmic or first division of the fifth nerve is sensory, and the 



268 CRANIAL NERVES. 

smallest branch of the ganglion. It is flattened, about 1 inch long, and 
runs in the outer wall of the cavernous sinus, being the lowest of the 
nerves. It receives filaments from the cavernous plexus, and gives off 
filaments to the third and sixth, and sometimes to the fourth nerve, and 
a recurrent branch running in the tentorium with the fourth. Finally it 
divides into the frontal, lachrymal, and nasal nerves, which pass through 
the sphenoidal fissure into the orbit. 

The lachrymal, the smallest, runs with the lachrymal artery above 
the external rectus muscle to the gland, which it supplies, as well as the 
conjunctiva, communicating with the superior maxillary nerve. It then 
pierces the palpebral ligament to end in the upper lid, joining branches 
of the facial. 

The frontal, the largest branch, enters the orbit through the widest 
part of the sphenoidal fissure, just below the periosteum, and divides 
about the middle of the orbit into the supra trochlear and supraorbital 
nerves. The former runs in over the pulley of the superior oblique, and 
leaves the orbit between it and the supraorbital foramen. It then ascends 
beneath the muscles and ends in the skin of the forehead. It communi- 
cates in the orbit with the infratrochlear nerve. The frontal nerve con- 
tinues as the supraorbital, which passes through the supraorbital foramen, 
supplies the upper lid, and divides into an inner and an outer branch. 
These ascend on the forehead and supply the pericranium and skin, the 
outer reaching nearly to the lambdoid suture. 

The nasal enters the orbit between the two divisions of the third nerve, 
and between the heads of the external rectus, and then crosses over the 
optic nerve and runs to the anterior ethmoidal foramen. In the orbit it 
gives off a branch to the ophthalmic ganglion, several long ciliary to the 
eyeball, and an infratrochlear branch. It then re-enters the cranial 
cavity through the anterior ethmoidal canal. In the cranium it runs 
in a groove on the cribriform plate, and through a slit on the side of 
the crista galli into the nose, where it gives off an external and an inter- 
nal branch. The latter supplies the mucous membrane of the septum, 
and the external the outer wall of the nasal fossa. The nerve then 
runs in the groove on the nasal bone to end as the anterior branch in 
the integument of the tip of the nose, joining facial branches. 

Describe the ophthalmic ganglion. 

It is found at the back of the orbit, between the optic nerve and the 
external rectus. It has three roots — viz. the long or sensory, from the 
nasal branch of the ophthalmic ; a short or motor, from the branch of 
the third to the inferior oblique ; and the sympathetic root, from the 
cavernous plexus. 

Branches : six or eight short ciliary, which run with the ciliary arteries 
above and below the optic nerve, and are joined by the long ciliary from 
the nasal. They pierce the sclerotic to supply the ciliary muscle and 
iris. 



269 

Describe the second division of the fifth (superior maxillary) 
nerve. 

It is sensory, and enters the foramen rotundum, crosses the spheno- 
maxillary fossa, and. as the infraorbital, traverses the canal, emerges 
from the foramen to end on the face in palpebral, nasal, and labial 
branches : the first, to lower lid ; the second, to side of nose ; and the 
third set, to upper lip. These branches join with the facial to form the 
infraorbital plexus. The superior maxillary nerve also gives off two 
brunches to Meckel's ganglion, an orbital and alveolar branches, and a 
recur rent branch to the dura mater. 

The orbital or temporo-malar branch enters the orbit by the spheno- 
maxillary fissure, and divides into two branches, which pierce the malar 
bone. The malar branch supplies the skin of the cheek, and joins the 
facial. The temporal branch, after piercing the malar bone, enters the 
temporal fossa, and ends in the skin over the fore part of the temporal 
region, joining the facial and auriculotemporal nerves. 

The alveolar or superior dental nerves are three. The posterior 
divides into two, which run on the zygomatic surface of the sup. maxilla, 
supplying the gum and the mucous membrane of the cheek, and enter 
the posterior dental canals to the molar teeth. The middle runs to the 
bicuspids along a canal in the antrum. The anterior descends in its 
canal, and [gives a nasal branch to the pituitary membrane, and dental 
branches to the canine and incisor teeth. 

Describe Meckel's ganglion. 

It is also called the spheno-palatine, and lies in the spheno-maxillary 
fossa, close to the spheno-palatine foramen and below the superior max- 
illary nerve. Its motor root comes from the facial (see Vidian nerve), 
its sensory root from the two ganglionic branches of the superior max- 
illary nerve, and the sympathetic root from the carotid plexus. Its 
branches are as follows : 

Ascending : Several through the spheno-maxillary fissure to the 
orbit. They may supply the periosteum. 

Descending" : The small or posterior runs with a small artery in the 
lesser palatine canal. It supplies the levator palati and azygos uvulae. 

The large or anterior runs in the posterior palatine canal, thence in 
branches to the incisor teeth along grooves in the hard palate, and one 
joins the naso-palatine nerve. It gives oft' inferior nasal branches, 
through canals in the palate bone, to supply the spongy bones. 

The external, to the outer part of the soft palate, through the exter- 
nal palatine canal. 

The internal branches include the naso-palatine and the upper nasal 
nerves. The latter run through the spheno-palatine foramen to the spongy 
bones and septum. The naso-palatine nerve proceeds with the above, 
and then descends on the septum nasi, beneath the pituitary membrane, 
and through the mesial divisions of the anterior palatine canal, called 



270 CRANIAL NERVES. 

the foramina of Scarpa, the left anterior to the right. They supply the 
mucous membrane behind the incisor teeth. 

The posterior branches are the Vidian and pharyngeal nerves. The 
Vidian passes back through the Vidian canal, and divides in the foramen 
lacerum medium into the great superficial petrosal and the great deep 
petrosal. The former passes through the foramen lacerum medium, 
runs in a groove on the anterior surface of the petrous portion of the 
temporal, enters the hiatus Fallopii, communicates with Jacobson's nerve, 
enters the aqueductus Fallopii, and joins the geniculate ganglion of the 
seventh nerve. The deep runs backward and joins the sympathetic in 
the carotid canal. 

The pharyngeal nerve passes through the pteiygo-palatine canal to. 
the mucous membrane of the pharynx. 

Describe the inferior maxillary nerve. 

It is the largest branch, and arises by two roots — a large sensory root 
from the Gasserian ganglion and the motor root of the fifth. This 
nerve divides into two trunks, anterior and posterior. The anterior 
gives off the masseteric, the buccal the deep temporal and the two 
pterygoid. 

The masseteric runs above the external pterygoid, crosses the sig- 
moid notch to masseter, supplying also filaments to the jaw. 

The deep temporal are three, the posterior, middle, and anterior. 

The buccal is a sensory nerve, and runs along the inner surface of the 
coronoid process to divide, on the buccinator, into branches to the 
muscles and skin joining the facial, and extending as far as the angle 
of the mouth. 

The pterygoid, internal and external, supply those muscles respec- 
tively. 

The posterior trunk of the inferior maxillary is mostly sensory. It 
divides into the auriculo-temporal, gustatory, and inferior dental. 

The auriculo-temporal runs beneath the external pterygoid, the 
middle meningeal artery passing up between its two roots of origin to 
the inner side of the neck on the lower jaw. It then passes up under 
the parotid gland, and along with the temporal artery over the z3 T goma, 
and divides into temporal branches to the skin of the temporal region, 
joining the facial. This nerve communicates at its origin with the otic 
ganglion, and gives oif the following branches : 

Auricular, the inferior to the external meatus, the superior to the 
tragus and pinna. 

Articular, one or two to the articulation of the jaw; several to the 
parotid, and the branches to the external auditory meatus send a fila- 
ment to the membrana tympani. 

The inferior dental nerve runs along with the artery, enters that 
canal, supplies the teeth, and at the mental foramen divides into an incisor 
and a mental branch. The former supplies the canines and incisors, the 
latter the skin of the chin and lower lip. The nerve is at first under the 



SUBMAXILLARY AND OTIC GANGLIA. 271 

external pterygoid ; later, between the ramus of the jaw and the internal 
lateral ligament. Its branehes are the mylo-hyoid and dental. The 

mylo-hyoid runs in the groove to supply the mylo-hyoid and anterior 
belly of digastric muscles. The dental supply the molars and bieuspids, 
interlacing to form a line plexus, the inferior dental. 

The gustatory or lingual nerve lies at first beneath the external 
pterygoid, internal to the dental nerve. Here a branch from the dental 
may cross the internal maxillary to join it. The chorda tympani also 
joins it. The nerve now runs along the inner side of the ramus of the 
jaw, and crosses the upper constrictor to the side of the tongue above 
the deep part of submaxillary gland ; lastly, it runs below Wharton's 
duct, and superficially along the side of the tongue to its apex. It 
communicates with the facial through the chorda tympani, the submax- 
illary ganglion, inferior dental, and hypoglossal. It supplies the mucous 
membrane of the mouth and tongue (anterior two-thirds), the gums, 
sublingual gland, and the filiform and fungiform papillae. 

Describe the submaxillary ganglion. 

It is placed above the deep part of the gland, and receives filaments 
from the gustatory and from the inferior maxillary nerve through the 
chorda tympani ; also filaments from the sympathetic plexus around the 
facial artery. 

Branches: Five or six to gland, Wharton's duct, and the mucous 
membrane of the mouth. 

Describe the otic ganglion. 

It is of a reddish coloi\ oval and flattened in form, and £ inch in 
diameter. It lies on the inferior maxillary nerve (deep surface) below 
the foramen ovale, and behind it is the middle meningeal artery. It 
communicates with the inferior maxillary through its internal pterygoid 
branch, with the small superficial petrosal nerve, and with the plexus on 
the middle meningeal artery. 

Branches : One to the_ tensor tympani, to tensor palati, to chorda 
tympani ; and to the •auriculo-temporal nerve two. 

Describe the sixth nerve. 

The sixth or abducens has an apparent origin in the groove be- 
tween the pons and medulla, and a deep origin from the fasciculus teres. 
It runs to the lower and outer part of the dorsum sellae, and traverses 
the floor of the cavernous sinus external to the carotid artery, and, re- 
ceiving branches from the cavernous and carotid plexuses, enters the 
orbit by the sphenoidal fissure between the two heads of the external 
rectus; it receives a branch from the ophthalmic nerve, and supplies 
the above-named muscles. 

What are the relations of the parts in the cavernous sinus and 
sphenoidal fissure? 

In the sinus: the third, fourth, and the ophthalmic branch of the 



272 CRANIAL NERVES. 

fifth lie in the outer wall, in numerical order from above downward and 
from within outward; with the sixth nerve, on the floor and external to 
the carotid artery. In the fissure: the fourth, with the frontal and 
lachrymal divisions of the ophthalmic, lie in this order from within out- 
ward and just below the periosteum. All the rest enter between the 
heads of the external rectus in this order from above downward: the 
upper division of the third ; nasal branch of the fifth ; lower division 
of the third ; and the sixth. The ophthalmic vein is below them all. 

Describe the seventh nerve. 

The seventh or facial has a superficial origin from the depression 
between the olivary and restiform bodies, and a deep from the fasciculus 
teres. Between it and the eighth is the pars intermedia, which joins 
the facial in the auditory canal. The nerve runs outward to the internal 
meatus, where it runs in a groove on the auditory nerve, enters the aque- 
ductus Fallopii, and emerges at the stylo-mastoid foramen. It presents 
within the aqueduct, near the hiatus Fallopii, a reddish enlargement, the 
geniculate ganglion. Outside the cranium it runs forward in the parotid 
gland, and divides behind the ramus into the cervico-facial and temporo- 
facial divisions. In the parotid and vicinity the radiating branches 
form the pes anscrinus. 

Communicating branches: In the internal auditory meatus, one or 
two communicating with auditory nerve. 

In the aqueduct it communicates with Meckel's ganglion by means of 
the large superficial petrosal ; with the otic ganglion by a small branch 
to the small superficial petrosal; with the sympathetic, on the middle 
meningeal, by the external petrosal ; and with the pneumogastric (auri- 
cular branch). 

Outside the cranium : it sends branches to the glosso-pharyngeal, 
carotid plexus, auricularis magnus, auriculo-temporal, and facial nerves. 

Branches of distribution : In the aqueduct: a tympanic branch to the 
stapedius, and the chorda tympdni. The latter arises close to the stylo- 
mastoid foramen, ascends in a small canal to the posterior wall of tym- 
panum, and then passes over the upper part of the membrane between 
the handle of the malleus and the incus, finally emerging through the 
canal of Huguier ; it then descends on the inner side of the internal lat- 
eral ligament of the jaw, and joins the gustatory nerve, through which 
its fibres reach the submaxillary ganglion and lingualis muscle. It re- 
ceives a branch from the otic ganglion before joining the lingual. 

Outside the cranium : the posterior auricular ascends between the ear 
and the mastoid, receives a branch from the vagus, one from the auricu- 
laris magnus, and one from the occipitalis minor, and divides into an 
auricular branch to the back of the auricle and retrahens, and an occip- 
ital branch to the occipito-frontalis. 

The digastric branches, to the posterior belly of the digastric, one join- 
ing the glosso-pharyngeal nerve; and a siylo-hyoid branch to the muscle, 
joining the carotid plexus. 



THE NINTH NERVE. 27:> 

The temporo-facial division crosses the external carotid artery and the 
temporo-maxillary vein in the upper part of the parotid, receives fila- 
ments from the auriculo-temporal nerve, and divides into three sets of 
branches — viz. temporal, malar, and intraorbital. 

The temporal branches supply the attolens and attrahens, occipito- 
i'rontalis. orbicularis, and corrugator supercilii. They communicate with 
tlie auriculo-temporal, temporal branch of superior maxillary, and supra- 
orbital nerves. 

The malar branches run to the outer angle of the orbit, supply the 
orbicularis and corrugator, joining the lachrymal and supraorbital, and 
some, to lower lid, join with the superior maxillary nerve (palpebral 
branches i. 

The infraorbital group, to the space between the orbit and mouth. 
They supply the buccinator, orbicularis oris, the levator labii superioris, 
the levator anguli oris, and nasal muscles. They unite with the cervico- 
facial branches, the nasal, infratrochlear, and with the superior maxillary 
nerve. The latter forms the infraorbital plexus. 

The cervico-facial division descends through the parotid, joining 
branches of the great auricular, and divides, near the angle of the jaw, 
into buccal, supramaxillary, and inframaxillary branches. 

The buccal cross the masseter, supply the buccinator and orbicularis 
oris, and join the infraorbital nerves and the buccal nerve from the in- 
ferior maxillary. 

The supramaxUlary, beneath the depressor anguli oris, supplies the 
inferior labial muscles, and joins branches of the inferior dental. 

The inframa.rilhirii pierces the deep cervical fascia, supplies the 
platysma, and forms arches in the suprahyoid region, joining the super- 
ficial cervical nerve. 

Describe the auditory nerve. 

The eighth or auditory is the special nerve of the sense of hearing. 
Superficially it appears at the lower border of the pons, external to the 
facial. It has two roots — one from the inner side of, and one from the 
front of, the restiform body. It runs to the internal auditory meatus 
with the facial nerve, the two being separated by the pars intermedia 
and the auditory artery. The nerve in the meatus divides into a coch- 
lear and a vestibular branch. 

Describe the ninth nerve. 

The ninth or glossopharyngeal arises superficially by several 
filaments from the groove between the olivary and restiform bodies at 
the upper part of the medulla ; deeply through the lateral tract to a 
gray nucleus in the floor of the fourth ventricle. 

The nerve runs in front of the flocculus to pass through the middle 
part of the jugular foramen with the vagus and spinal accessory, in a 
separate sheath, and here presents two successive ganglionic enlarge- 
ments, the jugular and the petrous ganglia. Outside the cranium it 
18— A. 



274 CRANIAL NERVES. 

passes between the jugular vein and the internal carotid artery, descend- 
ing in front of the latter, and beneath the styloid process and its mus- 
cles, to the lower border of the stylo-pharyngeus. It then crosses this 
muscle and divides into branches beneath the hyogjossus. In the jugu- 
lar foramen it grooves the lower border of the petrous portion of the 
temporal. 

The upper or jugular ganglion is of small size, and is formed in the 
outer part of the nerve, some fibres passing over but not joining it. 

The petrous ganglion is larger, and lies in a groove in the petrous 
bone, involving the entire trunk of the nerve. From it pass the tym- 
panic nerve and branches of communication to the vagus and sympa- 
thetic. That to the sympathetic joins the upper cervical ganglion. To 
the vagus, one joins its auricular branch and one its upper ganglion. 
Another branch perforates the posterior belly of the digastric, from a 
point just below the petrous ganglion, to join the facial close to the 
stylo-mastoid foramen. 

The tympanic (Jacobson's nerve) runs in a canal in the petrous portion 
to enter the tympanum through an aperture in its floor close to the inner 
wall, and divides into branches which groove the promontory and form 
the tympanic plexus. It gives a branch to the fenestra rotunda, fenestra 
ovalis, and to the Eustachian tube. The nerve finally emerges from the 
tympanum by a canal at its upper and back part, as the small superficial 
petrosal nerve. This latter enters the cavity of the skull by a small fora- 
men on the anterior surface of the petrous portion external to the hiatus 
Fallopii, and escapes by a small foramen in the great wing of the sphe- 
noid, sometimes the foramen ovale, to join the otic ganglion. 

The tympanic nerve sends a communicating branch to the carotid 
plexus, the small deep petrosal. 

Branches in the neck : 

The carotid branches run on the internal carotid to its commencement 
at the common carotid, joining the pharyngeal branches of the vagus 
and the sympathetic. 

The pharyngeal, three or four, pierce the superior constrictor to the 
mucous membrane of the upper pharynx. 

The muscular, to the stylo-pharyngeus. 

The tonsillitic. to the tonsil and soft palate, form the circulus tonsil- 
laris and join the palatine nerves. 

The lingual are the two terminal branches. One supplies the mucous 
membrane of the posterior third of the tongue and the circumvallate 
papillae ; the other, to the side of the tongue, joins the gustatory. 

Describe the pneumogastric nerve. 

The tenth, vagus, or pneumogastric, is both motor and sensory. 
Its apparent origin is by twelve to fifteen filaments below, and in the line 
of the origin of, the ninth ; its deep origin is from a nucleus in the lower 
part of the fourth ventricle. It passes through the jugular foramen in 
the same sheath with the spinal accessory, a partition separating them 



THE TENTH NERVE. 275 

from the ninth, and develops the ganglion of the root of the vagus. 
Emerging from the foramen, it forms the ganglion of the trunk of the 
Vagus, 

The ganglion of the root (ganglion jugulare) is gray in color and 
spherical, its diameter about 2 lines. It has branches of communica- 
tion with the accessory part of the spinal accessory, with the petrous 
ganglion of the ninth, with the facial, and with the superior cervical 
ganglion of the sympathetic. 

The ganglion of the trunk (ganglion cervieale) is larger, of a reddish 
color and cylindrical form. _ Its surface is crossed by the accessory por- 
tion of the eleventh, and it communicates with the hypoglossal, the 
upper two cervical, and the sympathetic nerves. 

The vagus then descends between the internal carotid artery and the 
jugular vein to the thyroid cartilage, then between the vein and the 
common carotid to the root of the neck. 

On the right side the nerve crosses the first part of the subclavian artery, 
descends behind the right innominate vein and alongside of the trachea, 
and spreads out into the posterior pulmonary plexus behind the root of the 
lung. Below, two cords emerge from this plexus and ramify on the 
oesophagus, forming, with branches from the left, the oesophageal plexus. 
Again forming a single trunk, the nerve descends on the back of the 
oesophagus to ramify on the posterior surface of the stomach. 

On the left side the nerve runs behind the left innominate vein, between 
the left carotid and subclavian arteries, and crosses the arch of the aorta. 
It forms the left posterior pulmonary plexus, assists to form the oesopha- 
geal plexus, and as a single trunk descends on the front of the oesophagus 
to ramify on the anterior surface of the stomach. 

Brunches: {a) In the jugular foramen: An auricular branch (Ar- 
nold's), from the jugular ganglion, receives a branch from petrous gan- 
glion of the ninth, traverses a small canal in the petrous portion of the 
temporal, crosses the aqueductus Fallopii, and communicates with the 
facial. It escapes through the auricular fissure, then divides into a branch 
to the auricle, and a second which joins the posterior auricular. A re- 
current branch from the jugular ganglion supplies the dura mater in the 
posterior fossa. 

(b) In the neck : A pharyngeal branch from the cervical ganglion, de- 
riving its fibres mainly from the spinal accessory, crosses the internal car- 
otid, and joins with glosso-pharyngeal and sympathetic in the pharyngeal 
plexus. This plexus supplies the muscles and mucous membrane of the 
pharynx. 

The superior laryngeal, from the lower ganglion, runs internal to the 
internal carotid vessels, receiving branches from the pharyngeal plexus 
and sjTnpathetic, and divides into the external and internal laryngeal 
nerves. 

The external runs beneath the sterno-thyroid to supply the crico-thy- 
roid. It supplies the inferior constrictor, and sends branches to the 
pharyngeal plexus and superior cardiac nerve. 



276 CRANIAL NERVES. 

The internal branch pierces the thyro-hyoid membrane to supply the 
mucous membrane of the larynx, and by a long branch joins a similar 
offset from the recurrent nerve behind the ala of the thyroid cartilage. 
A twig supplies the arytenoideus. 

The inferior or recurrent laryngeal on the right .side arises in front of 
the subclavian artery and winds backward around that vessel; on the left 
it arises in front of the arch of the aorta and winds backward around it. 
Both nerves ascend between the trachea and (esophagus, behind the 
common carotid and inferior thyroid arteries, to the lower border of the 
cricoid cartilage. They enter the larynx beneath the inferior constrictor, 
supplying all its intrinsic muscles excepting the erico-thyroid, and join 
the superior laryngeal. Each gives off cardiac nerves which join those 
from the vagus ami sympathetic; tracheal and cesoph'/fjeal branches, and 
one to the inferior constrictor. 

The cervical cardiac nerves, two or three, are divided into the superior, 
joining the cardiac branches of the sympathetic ; and the inferior, one 
on each side. The right lies in front of the innominate artery, and joins 
the deep cardiac plexus. The left, in front of the arch of the aorta, 
joins the superficial cardiac plexus. 

(c) In the chest : The thoracic cardiac branches, the right from the 
trunk of the vagus and from the recurrent branch, the left from the 
latter only. They join the deep cardiac plexus. 

Pulmonary nerves, two or three anterior, join the sympathetic and 
form the anterior plexus on the root of the lung. The posterior, larger 
and more numerous, join branches from the second, third, and fourth 
thoracic ganglia to form the posterior plexus. Offsets from these nerves 
accompany the bronchi throughout the lung. 

The oesophageal, above and below the preceding. The lower and 
larger branches come from the oesophageal plexus. 

(d) Gastric branches : These are the terminal branches of the vagi. 
The right, to the posterior surface, join the cceliac, splenic, and left renal 
plexuses. The left, to the anterior surface and lesser curvature, join the 
right nerve, the sympathetic, and the hepatic plexus. 

Describe the eleventh pair. 

The eleventh, or spinal accessory, consists of a spinal portion 
and an accessor)/ jyart to the vagus. The latter part arises as five or six 
filaments from the lateral tract of the medulla, below the origin of the 
vagus. It sends some filaments into the ganglion jugulare of the vagus, 
and joins that nerve below the ganglion cervicale, being continued, for 
the most part, into the pharyngeal and superior laryngeal branches. 

The spinal portion arises from the lateral column of the cord as low as 
the sixth cervical nerve, the fibres being connected with the anterior horn 
of gray matter. This part then ascends, between the posterior nerve-roots 
and the ligamentum denticulatum, through the foramen magnum, then 
out again by the jugular foramen, lying in the sheath of the vagus, and 
here communicates with the accessory portion. After its exit from the 



THE SPINAL NERVES. 277 

skull it crosses the internal jugular vein and pierces the sterno-mastoid 
to end in the trapezius. 

Describe the hypoglossal. 

The twelfth or hypoglossal nerve arises by ten to fifteen filaments 
from the groove between the pyramid and olivary body. The deep 

origin is from a nucleus in the floor of the fourth ventricle. The filaments 
form two bundles which pierce the dura separately and unite in the an- 
terior condylar foramen. The nerve descends behind the internal carotid 
artery and internal jugular vein, closely bound to the vagus, then passes 
forward between the artery and vein, and becomes superficial below the 
digastric, curving around the occipital artery. It now crosses the exter- 
nal carotid and lingual arteries, runs between the mylo-hyoid and hyo- 
glossus, communicates with the gustatory nerve, and after piercing the 
genio-glossus breaks up into filaments to the substance of the tongue. 

Branches of communication pass to the vagus, superior cervical gan- 
glion of sympathetic, to the loop between the first and second cervical, 
and to the gustatory nerves. 

Branches of distribution : 

Descendens noni leaves the nerve as it crosses the occipital artery, de- 
scends within or in front of the carotid sheath, and. joining the communi- 
cantes noni. forms a loop from which the sterno-hyoid and thyroid and 
both bellies of the omo-hyoid are supplied. Its origin can be traced to 
the first and second cervical nerves. 

The thyro-liyoid branch crosses the great cornu of the hyoid bone, to 
supply the muscle. 

Muscular branches pass to the stylo-glossus, hyo- and genio-hyoglossus, 
and genio-hyoid muscles. 

Meningeal branches run to the posterior fossa, leaving the nerve at 
the foramen. 

THE SPINAL NERVES. 

Name and describe the origin of the spinal nerves. 

The spinal nerves consist on each side, of eight cervical, twelve dorsal, 
five lumbar, five sacral, and one coccygeal, in all thirty-one pairs, which 
arise from the cord by two roots, anterior' and posterior^ The hitter are 
the larger and are supplied with ganglia. The suboccipital or first cervi- 
cal nerve has no ganglion. The two roots unite just beyond the ganglion, 
and the resulting trunk divides into two divisions, anterior^ and posterior, 
each containing fibres from both roots. The posterior division divides into 
an external and an internal branch. The anterior^ divisions in the dorsal 
region remain separate, but elsewhere they unite into plexuses. 

Describe the posterior divisions of the cervical nerves. 

That of the first or suboccipital does not divide into an external and 
internal branch. It crosses the atlas to the suboccipital triangle, and 



278 THE SPINAL NERVES. 

supplies the complexus, the obliqui, and posterior recti, a branch joining 
the second nerve. OF the other nerves, the external branches supply 
the splenius, transversalis colli, cervicalis ascendens, and trachelo-mas- 

toid. The internal, except that of the second, run inward : those of 
the third, fourth, and fifth, between the complexus and semispinalis, 
supply them and the multifidus and the skin over the trapezius. The 
internal branches of the sixth, seventh, and eighth run beneath the 
semispinalis, and supply no cutaneous branches. The internal branch 
of the second, known as the great occipital nerve, pierces the trapezius 
and complexus, supplies the latter, and runs with the occipital artery 
supplying the back of the head, and sends a branch to the small occipital. 

Describe the posterior divisions of the other spinal nerves. 

In the dorsal region the external branches increase in size from above 
downward, pierce the longissimus dorsi to supply the erector spinae group, 
and those of the lower six, the skin. The internal branches of the six 
upper supply the multifidus and semispinalis dorsi and the skin. The 
six lower internal supply the multifidus, but not the skin. 

In the lumbar region the internal branches end in the multifidus. 
The external supply the intertransverse muscles and erector spinae, and 
the upper three the skin over the gluteal region. 

In the sacral region, of the upper three, the internal branches end in 
the multifidus spinas, and the external anastomose with the fourth sacral 
and last lumbar. They send off filaments over the great sciatic ligament, 
finally ending in the skin by two branches. 

The last two do not divide, but join the coccygeal nerve. 

The posterior division of the coccygeal nerve ends with the above, and 
supplies the skin over the coccyx. 

Describe the anterior divisions of the spinal nerves. 

They are larger than the posterior. Each division is connected with 
the sympathetic. Those of the cervical, lumbar, and sacral nerves form 
plexuses. Those of the dorsal nerves for the most part remain separate. 
(See Brachial Plexus.) 

Describe the cervical plexus. 

It is formed by the anterior divisions of the upper four cervical nerves, 
which emerge between the scalenus medius and rectus anticus major. 
It lies upon the scalenus medius and levator anguli scapulae, beneath 
the sterno-mastoid. Each nerve except the first divides into a branch 
for the nerve above and one for the nerve below. The anterior division 
of the first (suboccipital) nerve grooves the atlas beneath the vertebral ar- 
tery, and joins the second, supplying the rectus lateralis and recti antici. 
It communicates with the sympathetic, vagus, and hypoglossal nerves. 

What are the branches of the cervical plexus ? 
Its branches are superficial and deep. 



THE SPINAL NERVES. 279 

The superficial are divided into ascending and descending. 

1. Ascending branches : 

(a) The superficialis colli, from the second and third nerves, crosses 
the sterno-mastoid, and divides under the platysma into two brandies. 
an upper and a lower, which ramify in the skin of the front of the neck, 
from the maxilla to the sternum, 

(b) The auricularis magnus, from the second and third, runs over 
the sterno-mastoid to the parotid region, and supplies facial branches to 
the skin over the parotid, a mastoid branch to the skin in that region, 
and auric/Jar branches to the lobule and back of the auricle. By these 
branches the nerve also communicates with the facial and small occipital. 

(c) The occipitalis minor, from the second and third (sometimes 
only the. second), runs along the posterior border of the sterno-mastoid 
to the head and supplies the scalp. It communicates with the great 
occipital and the great and posterior auricular nerves, and gives a branch 
to the auricle. 

2. Descending branches : these are the supraclavicular nerves. 
They arise from the third and fourth cervical, and divide into the stipra- 
sternal) supraclavicular, and supra-acromial branches, which descend 
between the trapezius and sterno-mastoid to supply the skin over the 
regions indicated by their names. 

The deep branches consist of an external and an interned series. 

The external include muscular, to the sterno-mastoid (from the 
second) ; trapezius, scalenus medius, and levator anguli scapulae (from 
the third and fourth), and communicating-, which join the spinal 
accessory within the sterno-mastoid and trapezius, and also between 
these two muscles. 

The internal are: communicating-, from the loop between the 
first and second, to the vagus, hypoglossal, and sympathetic, and a 
branch from the fourth to the fifth; 

Muscular, to the lateral and anterior recti muscles (from the first 
and second) ; 

Communicantes noni, generally two, one from second and one 
from third, pass under or over the internal jugular to join the descend- 
ing branch from the hypoglossal nerve ; 

Phrenic, from the third, fourth, and fifth, descends on the scalenus 
anticus, then between the subclavian artery and vein, and crosses the 
internal mammary artery. It then crosses the root of the lung and 
runs between the pericardium and mediastinal pleura to the dia- 
phragm; it communicates with the sympathetic, descendens noni, and 
the nerve to the subclavius. The right is deeper than the left, It 
runs external to the innominate vein and superior vena cava. The left 
crosses the front of the aortic arch and the left vagus. Both phrenics 
supply the diaphragm, pleura, and pericardium. Filaments from the 
right, w T ith the phrenic branches of the solar plexus, form a ganglion 
which sends branches to the suprarenal capsules and inferior vena cava 
and to the hepatic plexus ; on the left side there is no ganglion. 



280 THE SPINAL NERVES. 

Describe the brachial plexus. 

Formed by the anterior divisions of the lower four cervical and first 
dorsal, as follows: the fifth and sixth form an upper: the seventh, a 
middle ; and the eighth cervical with first dorsal a lower trunk. Each 
of these trunks then separates into an anterior and a posterior branch. 

The anterior branches of the upper and middle trunks form the outer 
cord of the plexus ; the anterior branch of the lower, the inner cord: of 
the posterior cord it is variously stated that the posterior branches of all 
three trunks form it, or that the posterior branches of the upper and 
middle trunks form it, while the posterior branch of the lower trunk 
joins the niusculo-spiral nerve. It is altogether a matter of dissection. 

The plexus is at first between the anterior and middle scaleni, then 
above and external to the subclavian artery. It passes behind the clavicle 
and subclavius, lying on the subscapulars and serratus magnus. The 
cords lie external to the first part of the axillary artery, but surround the 
second part of that vessel. 

What are the branches of the brachial plexus ? 

Branches above the Clavicle : a branch from the fifth joins the 
phrenic, and muscular branches supply the scaleni, longus colli, rhoin- 
boidei, and subclavius. The branch to the subclavius, from the trunk 
formed by the fifth and sixth cervical, crosses the subclavian artery, its 
third part, and sends a branch to the phrenic nerve. 

The posterior thoracic nerve from fifth and sixth cervical runs out 
of the scalenus medius and descends behind the clavicle upon the ser- 
ratus magnus, which it supplies. 

The suprascapular nerve, from the fifth and sixth, enters the supra- 
spinous fossa by the notch, supplies an articular branch and one to the 
muscle, also a branch to the infraspinous fossa and muscle. 

Branches below the Clavicle: the three cords give off the follow- 
ing nerves: the outer, the musculo-cutaneous, outer head of median, ex- 
ternal anterior thoracic; the inner, the internal anterior thoracic, inner 
head of median, internal and lesser internal cutaneous, and the ulnar; 
the posterior, the musculo-spiral and circumflex and subscapular. 

Describe the thoracic and subscapular nerves. 

The anterior thoracic nerves supply the pectoral muscles. The 
external crosses the axillary artery and gives a branch to the inner nerve, 
and the internal runs forth between the artery and vein, and joins the 
branch from the external, forming a loop around the artery. 

The subscapular : the upper supplies the subscapulars at its upper 
part; the middle or long accompanies the subscapular artery to the 
latissimus dorsi; and the lower supplies the subscapulars and teres 
major. 

Describe the internal "cutaneous" nerves. 

The internal cutaneous, on the inner side of the axillary artery. 



THE SPINAL NERVES. 281 

divides at the middle of the arm into an anterior branch, crossing over 
or under the median basilic vein, which supplies the forearm as far as 

the wrist, and ^posterior, which winds above t lie inner condyle to back 
of humerus, and runs to lower part of forearm. This nerve communi- 
cates with the lesser nerve and the ulnar, and supplies the skin over the 
biceps. 

The lesser internal cutaneous (of Wrisberg) runs behind and 
then internal to the axillary vein and joins the intercosio-lnuneral nerve. 
It then runs along the inner side of the brachial artery, and supplies the 
skin as far as the olecranon and internal condyle. 

The intercosto-humeral bears a complementary relation, in point of 
size, to the lesser nerve, and may even replace it altogether. 

Describe the circumflex and musculo-cutaneous nerves. 

The circumflex nerve, behind the axillary artery, winds back through 
the space bounded by the triceps, humerus, and the two teretes muscles, 
gives a filament to the shoulder-joint, and divides into two branches, an 
upper and a lower. The former winds around the humerus to the an- 
terior border of the deltoid, supplying it and the skin, and the latter 
supplies the skin over the lower two-thirds of the deltoid as well as the 
muscle, and gives a branch to the teres minor upon which a ganglion is 
developed. 

The external or musculo-cutaneous nerve arises opposite the lower 
border of the pectoralis minor, and runs through the coraco-brachialis 
and over the brachial is anticus to pierce the fascia at the outer border 
of the biceps. It then runs behind the median cephalic vein and divides 
into two branches, anterior and posterior. 

In the arm it supplies the three muscles mentioned above, a filament 
to the elbow-joint, and one to the humerus. 

The anterior branch crosses the radial artery at wrist and joins a branch 
of the radial nerve and the palmar cutaneous branch of the median. It 
supplies the skin over the radius and twigs to the artery. The posterior 
branch descends along the back of the forearm to the wrist and joins 
branches of the radial and musculo-spiral nerves. 

Describe the median nerve. 

It arises by two roots, an outer from the outer cord and an inner from 
the inner cord, which unite in front of the axillary artery. It crosses 
over (or under) the brachial artery to its inner side. It enters the fore- 
arm between the tw 7 o heads of the pronator teres, running on the flexor 
profundus and beneath the annular ligament into the hand. At the 
wrist it lies behind and to the ulnar side of the palmaris longus. 

Describe its branches. 

Branches: in the arm, none. 

In the forearm it supplies all the superficial flexor muscles except the 
flexor carpi ulnaris ; some filaments to the elbow T -joint ; 



282 THE SPINAL NERVES. 

The anterior interosseous nerve. This runs along the interosseous 
membrane with the artery of that name. It supplies the flexor longus 
pollicis and the outer half of the flexor profundus digitorum muscles, 
between whieh it lies, and also the pronator quadratus, in which it 
ends. 

The palmar cutaneous branch pierces the fascia above the annular 
ligament, and supplies the skin over the ball of the thumb and the palm. 
It communicates with branches of the ulnar and external cutaneous 
nerves. 

In the palm : the nerve lies on the flexor tendons, covered by the an- 
nular ligament, and becomes larger and reddish in color. It divides into 
two branches — the external, supplying some of the muscles of the thumb 
and digital branches to the thumb and index finger ; and the internal, 
supplying digital nerves to the index, middle, and ring fingers. 

The muscular branches supply the abductor, opponens, and outer head 
of the flexor brevis pollicis. The first digital, with the second, supplies 
the thumb, the former joining a branch of the radial. The third, along 
the radial side of the index finger, supplies it and the first lumbricalis. 
The fourth supplies the adjacent sides of the index and middle fingers 
and the second lumbricalis. The fifth, to the adjacent sides of the middle 
and ring fingers joins a branch of the ulnar. Each digital nerve divides 
at the tip of the finger into a branch to the pulp and one to the matrix 
of the nail. At the base of the first phalanx each sends a branch to 
the back of the second and third phalanges. 

Describe the ulnar nerve. 

The ulnar runs internal to the axillary and brachial arteries as tar as 
the middle of the arm. It then passes to the groove between the olec- 
ranon and internal condyle with the inferior profunda artery, and runs 
between the two heads of the flexor carpi ulnaris, lying beneath the 
muscle above and to the radial side of it below. In the lower two- 
thirds of the forearm the ulnar artery is external. The nerve then 
crosses the annular ligament between the artery and pisiform bone, and 
divides into a superficial and a deep branch. 

Describe its branches. 

Branches : In the arm, none. 

In the forearm, several articular to the elbow. Muscular, to the 
flexor carpi ulnaris and inner half of the flexor profundus. Two cuta- 
neous, by a common trunk. One joins a branch of the internal cuta- 
neous, and the other, the palmar cutaneous, runs on the ulnar artery to 
the palm, joining branches of the median nerve. 

The dorsal cutaneous runs backward beneath the flexor carpi ulnaris, 
and supplies dorsally the little and inner half of the ring finger. The 
latter communicates with the contiguous branch of the radial. 

In the palm : the superficial and deep branches. The former supplies 
the skin and palmaris brevis and digital branches to the little and inner 



THE SPINAL NERVES. 283 

half of the ring fingers, the latter joining a branch of the median. The 
latUr. passing between flex. brev. and abductor min. digit, supplies all 
the muscles of the hand except those supplied by the median nerve, and 
sends filaments to the wrist -joint. 

Describe the musculo-spiral nerve. 

It runs behind the axillary and brachial vessels, and, later in the mus- 
culo-spiral groove with the superior profunda artery, then between the 
brachialis amicus and supinator longus. In front of the outer condyle 
it divides into the radial and posterior interosseous nerves. 

Branches : muscular and cutaneous. 

Muscular branches: the internal supplies the inner and middle heads 
of the triceps; the posterior supplies the outer head of the triceps and 
the anconeus; the external supplies the supinator longus, extensor carpi 
radialis longior, and the brachialis anticus. 

Cutaneous branches : the intern al supplies the inner side of the pos- 
terior aspect of the arm ; of the two external, the upper supplies the 
lower part of the upper arm ; the lower, the lower half of the arm, fore- 
arm and wrist dorsally, joining the posterior branch of the musculo- 
cutaneous. 

Describe the radial and posterior interosseous nerves. 

The radial, beneath and parallel w 7 ith the supinator longus, finally 
runs backward beneath its tendon, just above the wrist, pierces the fascia, 
and divides into two branches. Of these, the external supplies the radial 
side and ball of the thumb, and joins a branch of the musculo-cutaneous ; 
the internal, after communicating with the musculo-cutaneous, supplies 
dorsally digital branches to the thumb and index, index and middle, 
middle and outer half of the ring fingers. 

This last joins with the contiguous branch of dorsal cutaneous of ulna, 
and they all terminate at base of second phalanx. 

The posterior interosseous pierces the supinator brevis, and runs 
beneath the superficial muscles on the back of the forearm and on the 
lower part of the interosseous membrane. It supplies ail the muscles 
of the back and outer part of the forearm except the supinator longus, 
extensor carpi radialis longior, and the anconeus, and terminates at the 
wrist in a ganglion from which are supplied the carpal ligaments and 
joint. 

Describe the anterior divisions of the dorsal nerves. 

First dorsal : the anterior division in part joins the brachial plexus, 
and the remainder of the nerve forms the first intercostal, which has no 
lateral cutaneous branch. 

The upper six are called the pectoral intercostal nerves, and lie below 
the vessels. At first they run between the pleura and the external in- 
tercostal muscles, then between the two planes of muscles to the middle 
of the rib, here giving off the lateral cutaneous nerves. The nerves 



284 THE SPINAL NERVES. 

now enter the substance of the internal intercostals as Tar as the cartilages, 
where they lie between the muscles and the pleura. Finally they cross 
the internal mammary vessels and the triangularis sterni, pierce the 
internal intercostals and pectoralis major, and end in the skin of the 
chest, as the anterior cutaneous nerves of the thorax. 

Branches: muscular^ to the intercostals, triangularis, levatores costa- 
rum, and serratus posticus superior. 

The lateral cutaneous are given off about midway to the sternum, 
pierce the serratus magnus and external intercostals, and each divides 
into two branches, anterior and posterior. 

The anterior runs to the skin over upper part of the external oblique, 
mamma, and skin ; the posterior, to the skin over the scapula and latis- 
simus dorsi. 

The lateral cutaneous of the second dorsal crosses to the arm. joins 
the nerve of Wrisberg, pierces the fascia, and supplies the skin of the 
upper half of the inner and back part of the upper arm, joining the 
cutaneous branch of musculo-spiral nerve. This nerve is generally called 
the intercosto-humeral. It has no anterior division. 

The lower six, or abdominal intercostals, run from the intercostal 
spaces behind the cartilages, between the internal oblique and transver- 
salis, to the rectus, which they enter. They supply the intercostals, ser- 
ratus posticus inferior, abdominal muscles, and end in the skin, as the 
anterior cutaneous nerves of the abdomen. 

The lateral cutaneous branches have a similar distribution to 
those in the chest. 

The last dorsal nerve is altogether abdominal. It crosses the quad- 
ratus lumborum and runs in the abdominal wall like the lower inter- 
costals. It communicates with the ilio-hypogastric and with the first 
lumbar nerve [dor si-lumbar). Its lateral cutaneous branch supplies 
the skin of the forepart of the gluteal region as low as the great tro- 
chanter. 

Each dorsal nerve is joined by short communicating branches from the 
sympathetic. 

Describe the anterior divisions of the lumbar nerves. 

The first unites with a branch from the last dorsal, the dorxi-lumhar 
nerve, and then proceeds, together with the second, third, and fourth, to 
form the lumbar plexus. The fifth joins the sacral plexus. They are 
joined by sympathetic filaments, and furnish branches to the psoas and 
quadratus muscles. 

Describe the lumbar plexus. 

It is formed in the substance of the psoas muscle, in the following 
manner: Each of the first four lumbar nerves divides into an upper and 
a lower branch. Just before dividing the first receives the dorsi-lumbar 
nerve, and the third and fourth send each a branch to the nerve below. 

The upper branch of the first subdivides into the ilio-hypogastric and 



THE SPINAL NERVES. 



285 



ilioinguinal nerves. The lower branch of the first passes downward 
and subdivides into two branches, one of which unites with the upper 
branch of the second to form the genito-erural nerve. The other unites 
with the lower branch of the second to form a cord. This cord passes 
downward, and gives off the external cutaneous nerve and a branch to 
the obturator, after which it unites with the upper branches of the third 
and fourth to form the anterior crura/ nerve. The lower branches of the 



third and fourth unite to form the obturator nerve. (See Fis 

Fig. 15. 

OORSI LUMBRRN 



i^LUMBRRN 



3* D LUMBRRN 
4 r " LUMBRRN 

LUMBRR N. 



15.) 




EXT. CUT N 



flNJ.CRURRL H 



OBTURRTORN. 



Describe the ilio-hypogastric and ilio-inguinal nerves. 

The ilio-hypogastric escapes at the upper part of the psoas, crosses 
the quadratus, pierces the transversalis at the iliac crest, and divides, 
between it and the internal oblique, into two branches. The iliac branch 
supplies the skin over the glutei, behind the lateral cutaneous of last 
dorsal ; the hypogastric branch communicates with the ilio-inguinal, and 
pierces the oblique muscles to supply the skin of the pubic and hypo- 
gastric regions. 

The ilio-inguinal crosses the quadratus and iliacus below the pre- 
ceding, pierces the transversalis, communicating with the ilio-hypogastric, 
and runs in the inguinal canal, supplying the skin of the groin, scrotum, 
and penis (the labium in the female). 

Describe the genito-erural and external cutaneous nerves. 
The genito-erural runs downward through and on the psoas muscle, 



286 THE SPINAL NERVES. 

and divides some distance above Poupart's ligament into a genital and 
a crural branch. The former lies on the external iliac artery, sending 
filaments around it, and runs with the cord through the inguinal canal 
to the cremaster muscle ; in the female it runs on the round ligament. 
The crural branch runs under Poupart's ligament into the thigh, send- 
ing filaments around the femoral artery, and lying superficial to the artery 
in the femoral sheath. It supplies the skin of the upper thigh, and 
joins the middle cutaneous. 

The external cutaneous crosses the iliacus and enters the thigh 
through the notch below the anterior superior spine of the ilium, divid- 
ing into an anterior and a, posterior branch. The former runs in a canal 
within the fascia lata, and becomes cutaneous 4 inches below Poupart's 
ligament. It supplies the front and outer part of the thigh to the knee, 
sometimes joining in the patellar plexus. The posterior branch supplies 
the skin of the outer and back part of the thigh halfway to the knee. 

Describe the obturator nerve. 

The obturator nerve emerges from the inner border of the psoas at the 
pelvic brim. It runs above the obturator vessels to escape at the upper 
part of the obturator foramen, dividing into two branches separated by the 
adductor brevis. The anterior runs beneath the pectineus and adductor 
longus, joining at the lower part of the latter with branches of the long 
saphenous and internal cutaneous nerves to form a plexus. A branch 
supplies the hip-joint ; muscular branches to gracilis and adductor longus. 
sometimes to the adductor brevis and pectineus; the terminal branch 
to the femoral artery. 

The posterior branch pierces the obturator externus and runs behind 
the adductor brevis on the adductor magnus, and supplies these muscles. 
A branch to the knee-joint pierces the magnus, lies on the popliteal artery, 
sending branches to it, and pierces the ligamentum Winslowii to supply 
the synovial membrane. 

The accessory obturator arises by branches from the second, third, and 
fourth nerves, or is a branch of the obturator. It runs along the inner 
border of the psoas, and, crossing the pubes. divides beneath the pecti- 
neus into three branches — one to the anterior branch of the obturator, 
another to the hip-joint, and a third to the pectineus. It is not constant. 

Describe the anterior crural nerve. 

It is the largest branch of the lumbar plexus. It enters the thigh 
between the psoas and iliacus, external to the femoral artery, and divides 
into. an anterior (mainly cutaneous) and a pernor (mainly muscular) 
portion. 

Branches : 

Within the abdomen, three or more branches to the iliacus, and a 
branch to the femoral artery. 

Anterior portion : 

(a) The middle cutaneous pierces the fascia lata 4 inches below Pou- 



THE SPINAL NERVES. 287 

part's ligament, and divides into two branches which run on the front of 
the thigh to the patella. It joins the crural branch of the genito-crural 
and the internal cutaneous nerves. 

(b) The internal cutaneous crosses the femoral artery and divides into 
two branches, anterior and posterior. It supplies several cutaneous fila- 
ments which follow the course of the long saphenous vein, one reaching 
to the knee. The anterior branch runs to the knee, perforating fascia 
lata low down, and, crossing the patella to its outer side, communicates 
with a branch of the long saphenous nerve. The posterior branch runs 
along the posterior border of the sartorius, communicates with the in- 
ternal saphenous nerve, and supplies the, skin of the inner side of the 
thigh (lower part) and leg. It perforates fascia lata at inner side of 
knee. It also joins branches of the obturator beneath the fascia. 

(c) Branch to the pectineus passing behind the femoral vessels. 
id) Branches to the sartorius from the middle cutaneous. 
Posterior Portion: 

(a) Branch to the rectus femoris ; also sends a twig to the hip-joint. 

(b) Branch to the vastus externus. 

(c) Branches to the crureus: one of these sends a filament to the 
knee-joint. 

(d) Branch to the vastus internus accompanies the saphenous nerve 
and sends a filament to the knee-joint, 

(e) The internal saphenous nerve accompanies the femoral vessels, 
being at first external to, and later crossing, the artery. It then runs 
beneath the sartorius to the inner side of the knee, pierces the fascia, 
and accompanies the saphenous vein along the inner side of the leg. 
Passing in front of the inner ankle, it ends on the inner side of the 
metatarsus. It communicates with the obturator and internal cuta- 
neous. 

Branches supply the skin of the leg. The terminal branches commu- 
nicate with the musculo-cutaneous, and a patellar branch spreads out 
over the knee and joins in the patellar plexus. 

Describe the anterior divisions of the sacral and coccygeal nerves. 

The anterior division of the fifth lumbar receives a branch from the 
fourth, and, under the name of the lumbosacral cord, joins the first 
sacral. 

The anterior divisions of the first four sacral nerves escape by the 
anterior sacral foramina; the fifth, between the sacrum and coccyx; all 
join with filaments from the sympathetic. 

The first three, with a branch from the fourth, enter into the forma- 
tion of the sacral plexus. 

The fourth, its remaining portion, sends branches to the bladder and 
adjacent viscera, and supplies the levator ani. coccygeus, external 
sphincter, and skin of the perineum. It also sends a branch to the fifth 
sacral. The visceral branches unite with occasional branches from the 
third sacral and with the sympathetic. 



288 THE SPINAL NERVES. 

The fifth sacral pierces the coccygeus, supplying it and the skin over 
the coccyx. Branches from the fourth sacral and the coccygeal nerve 
join it. 

The anterior division of the coccygeal nerve, very small, pierces the 
coccygeus and sacro-sciatic ligaments, and terminates by uniting with the 
fifth sacral. 

Describe the sacral plexus and enumerate its branches. 

It is formed by the anterior divisions of the first, second, thirds and 
part of the fourth sacral nerves, together with the lumbo-sacral cord. 
The lumbo-sacral cord, with the first, second, and parr of the third 
sacral nerve, is continued into the upper great branch of the plexus, 
and the remainder of the plexus forms the lower or smaller branch. 

Branches: besides these two principal branches, which are, respect- 
ively, the great sciatic and the pudic nerves, the upper nerves of the 
plexus give off the nerves of the pyriformis, quadratus femoris, obtu- 
rator internus, and gemelli, as well as the superior and inferior gluteal, 
small sciatic, and a perforating cutaneous branch. 

Describe the muscular branches. 

The muscular branch to the obturator internus crosses the spine of the 
ischium and enters the small sciatic foramen to the inner surface of the 
muscle. It also supplies the superior gemellus. That to the quadratus 
femoris runs beneath the tendon of the obturator internus, and supplies 
also the inferior gemellus and hip-joint. Lastly, the pyriformis receives 
several filaments from the sacral nerves previous to the formation of the 
plexus. 

Describe the gluteal nerves. 

The superior gluteal emerges above the pyriformis. through the 
great sciatic notch, and divides into an upper branch, to the gluteus 
medius, and a lower, larger branch, which supplies both the medius and 
minimus, piercing the latter to end in the tensor vaginae femoris. It 
arises from the lumbo-sacral cord and first sacral nerve. 

The inferior gluteal emerges below the pyriformis, dividing into 
numerous branches for the gluteus maximus. It sends a branch to join 
the small sciatic. It arises from the lumbo-sacral cord and first and 
second sacral nerves. 

Describe the small sciatic and perforating cutaneous nerves. 

The small sciatic appears below the pyriformis. and runs beneath 
the gluteus maximus upon the great sciatic nerve, thence beneath the 
fascia lata, which it pierces just below the knee. It communicates with 
the external saphenous nerve. It arises from the second and third 
sacral nerves. 

Branches: cutaneous, to the calf of the leg, to the inferior gluteal 
region, and to the back and inner part of the thigh (femoral cuta- 



THE SPINAL NERVES. 289 

neous) ; and the inferior pudendal nerve, derived below the tuber ischii, 
to tlu j scrotum or labium majus and the skin of the upper and inner 
part of the thigh. 

The perforating- cutaneous nerve, from the fourth sacral nerve, 
pierces the great sciatic ligament and turns over the lower border of the 
gluteus maximus to supply the skin over its lower part. 

Describe the pudic nerve. 

The pudic nerve emerges between the coccygeus and pyriformis, 
and crosses the ischial spine to re-enter the pelvis by the lesser sacro- 
sciatic foramen. It divides, in the ischio-rectal fossa, into the inferior 
hemorrhoidal^ perineal, and dorseil nerve of the penis vel clitoridis. 

The inferior hemorrhoidal supplies the external sphincter and the skin 
of the back part of the perineum, communicating with the pudendal 
and perineal nerves. 

The perineal runs in a sheath of the obturator fascia along the outer 
wall of the ischio-rectal fossa, and divides into superficial and deep 
branches. The latter supply the external sphincter and the muscles of 
the perineum, sending a branch to the mucous membrane of the urethra, 
which pierces the corpus spongiosum. 

The superficial branches are external and internal. The former sup- 
plies the scrotum and inner side of the thigh, and the latter runs nearer 
to the middle line and supplies the skin of scrotum. Both the super- 
ficial perineal nerves communicate with the pudendal and hemorrhoidal 
branches, and in the female end in the labia majora. 

The dorsal nerve of the penis (in the female of the clitoris) accom- 
panies the pudic artery, and runs along the dorsum to the glans. It 
supplies branches to the constrictor urethrae, to the integument of the 
penis, and to the corpus cavernosum. On the penis it receives branches 
from the sympathetic. In the female the analogue of this nerve is 
smaller, with a like distribution. 

Describe the great sciatic nerve. 

This is the largest nerve in the body, and includes fibres from the 
greater part of the sacral plexus. From the lower border of the pyri- 
formis it descends on the gemelli, obturator interims, and quadratus, 
then on the adductor magnus, being covered by the gluteus maximus 
and long head of the biceps, and accompanied by the small sciatic nerve 
and the sciatic artery. It divides at the lower third of the thigh into 
the external and internal popliteal nerves. It supplies the biceps, senii- 
tendinosus and semimembranosus, adductor magnus, and hip-joint. 

Describe the internal popliteal nerve. 

This is the larger branch of bifurcation of the great sciatic. It runs 
along the middle of the popliteal space to the lower border of the pop- 
liteus, where it becomes the posterior tibial. It is at first external to, 
then behind, and lastly internal to, the popliteal artery. 
19— A. 



290 THE SPINAL NERVES. 

Branches: three articular, one accompanying the az.ygos articular 
artery, and one each the upper and lower articular arteries on the inner 
side of the knee-joint. 

Muscular: one to each head of the gastrocnemius, to the plantaris, 
to the soleus, and to the popliteus. The latter gives filaments to the 
tibia and interosseous membrane, and turns beneath the lower border 
of the muscle. 

Cutaneous : the external or short saphenous nerve, or tibial communi- 
cating. It runs between the two heads of the gastrocnemius, pierces 
the fascia about halfway down the calf, and receives the peroneal com- 
municating nerve from the external popliteal. It then runs in company 
with the short saphenous vein, along the outer border of the tendo 
Achillis and below the outer malleolus, to end in the skin of the outer 
side of the foot and little toe, communicating with the musculocuta- 
neous nerve. 

Describe the posterior tibial nerve. 

The posterior tibial nerve is the continuation of the internal popliteal 
from the lower margin of the popliteus. It is successively internal, be- 
hind, and external to the artery, and divides between the inner ankle 
and heel into the two plantar nerves. 

Branches: articular, to the ankle. 

Muscular: one each to the tibialis posticus, flexor longus digitorum, 
flexor longus pollicis, and the soleus. 

A cutaneous branch pierces the internal annular ligament to supply 
the skin of the heel and back part of the sole. 

Describe the plantar nerves. 

The internal plantar nerve runs beneath the abductor pollicis, 
then between it and the flexor brevis pollicis, and divides into its 
digital branches. 

Branches : muscular, to the abductor pollicis and flexor brevis digi- 
torum. 

Cutaneous, to the skin of the sole. 

Digital branches as follows : the first, to the inner side of the great 
toe, supplies the flexor brevis pollicis ; the second, to the great and sec- 
ond toes, supplies the first lumbricalis; the third, to the second and third 
toes, supplies the second lumbricalis ; and the fourth, to the third and 
the inner side of the fourth toe, communicating with the external plan- 
tar. _ Each digital nerve supplies cutaneous and articular branches and 
terminates as in the hand. 

The external plantar runs between the flexor accessorius and the 
flexor brevis digitorum, dividing between the latter and the abductor 
minimi digiti into a superficial and a deep branch. Before dividing it 
supplies the flexor accessorius and abductor minimi digiti. 

The superficial gives a digital branch to the outer side of the little toe, 
which supplies its short flexor and sometimes also the interossei of the 



THE SPINAL NERVES. 291 

fourth space, and another digital branch to the adjacent sides of this toe 
and the fourth. 

The deep branch dips under the accessorius and flexor muscles, and 
supplies all the dorsal and plantar interossei except, occasionally, those 
of the fourth space; it also supplies the outer two lunibricalcs, the ad- 
ductor pollicis, and the transversus pedis. 

Describe the external popliteal nerve. 

The external popliteal or peroneal nerve runs between the 
biceps muscle and outer head of the gastrocnemius, turns round the 
fibula below its head and beneath the peroneus longus, and divides 
into the anterior tibial and the musculocutaneous nerves. 

Branches: articular, with the upper and lower external articular 
arteries, and occasionally a recur rent articular branch, with the recurrent 
tibial artery, reaches the joint. 

Cutaneous, two in number, supply the skin of the outer and back 
part of the leg; and another, the peroneal communicating, joins the 
short saphenous nerve. 

Describe the musculocutaneous nerve. 

The niusculo-cutaneous nerve runs between the extensor longus 
digitorum and the peronei, and pierces the fascia at the lower part of 
leg, dividing into two branches, external and internal, for the toes. 

Branches: muscular, to the peroneus longus and brevis ; cutaneous, 
to the lower part of the leg. 

The terminal branches: of these, the internal runs on the dorsum of 
the foot and supplies the adjacent sides of the second and third toes and 
the inner side of the great toe. It communicates with the long saph- 
enous and anterior tibial nerves. 

The external supplies the fourth toe, together with the contiguous 
sides of the third and fifth. It communicates with a branch of the 
short saphenous nerve. 

Describe the anterior tibial nerve. 

The anterior tibial nerve, from between the peroneus longus and 
fibula, runs along the front of the interosseous membrane with the 
artery to the ankle, where it divides into an external and an internal 
branch. It is at first external, then in front, and below again external 
to the artery. 

Branches: muscular, to the tibialis anticus, extensor longus digitorum, 
extensor proprius, and the peroneus tertius ; articular, to ankle ; and its 
terminal branches. Of these — 

The external runs under the extensor brevis digitorum, and supplies it 
as well as the neighboring joints. 

The internal accompanies the dorsal artery of the foot to the first 
interosseous space, and supplies the skin of the great and second toes, 
joining a branch of the musculo-cutaneous. Both these nerves send 
interosseous branches to the metatarso-phalangeal joints. 



292 THE SYMPATHETIC NERVOUS SYSTEM. 

THE SYMPATHETIC NERVOUS SYSTEM. 

Describe the general arrangement of the sympathetic nervous 
system. 

The sympathetic nervous system consists of a series of ganglia, cords, 
and plexuses, with their communicating and distributing nerve-fibres. 
Its nerves supply all the viscera and the coats of the blood-vessels. 

There are two principal gang-Hated cords, lying one on each side 
of the spine from the base of the skull to the coccyx. They consist of 
a series of ganglia connected by short single or double cords. The num- 
ber of the ganglia corresponds in general to that of the vertebrae in the 
several regions, except in the neck, where there are but three. 

Below, these cords end on the front of the coccyx by a loop on which 
« the ganglion impar, and above they are connected with the carotid 
plexus in the carotid canal. 

The ganglia are connected with the spinal ncrccs by gray and white 
fibres, the former passing from the ganglia to the spinal nerves, and 
the latter vice versa. The ganglia are also connected together by gray 
and white fibres, the latter being continuous with the fibres of the spinal 
nerves prolonged to the ganglia. 

There are three great plexuses, consisting of nerves and ganglia. 
They are single and lie in front of the spine in the thoracic, abdominal, 
and pelvic regions, and each is named, from above downward, the car- 
diac, epigastric, and hypogastric plexus. 

Describe the cervical part of the gangliated cord and the supe- 
rior cervical ganglion. 

The cervical part consists of three ganglia, named superior, middle, 
and inferior, on each side. 

The superior, opposite the second and third cervical vertebrae, is red- 
dish-gray in color, fusiform in shape, and lies on the rectus anticus major 
behind the internal carotid vessels. 

Branches : an ascending branch runs alongside the internal carotid 
artery, and in the canal separates into an outer division, forming the 
carotid plexus, and an inner, forming the cavernous plexus. 

The carotid plexus lies external to the artery. It sends one or more 
filaments to the sixth nerve as it lies alongside the artery, and some to 
the G-asserian ganglion ; to the sphenopalatine ganglion it sends the 
large deep petrosal nerve, which joins the large superficial petrosal to 
form the Vidian ; it also sends the small deep petrosal, which communi- 
cates with Jacobson's nerve by joining the tympanic plexus. 

The cavernous jrfe.nts, in the cavernous sinus, lies below and internal 
to the internal carotid. It sends a branch to the third nerve, one to the 
fourth, several to the ophthalmic division of the fifth, the sympathetic 
root to the ophthalmic ganglion, and filaments to the pituitary body. 

Both these plexuses supply terminal filaments which form plexuses on 
the ophthalmic and cerebral arteries and sub-branches: 



THE SYMPATHETIC NERVOUS SYSTEM. 293 

A descending branch to the middle cervical ganglion. 

External branches to the first four spinal nerves, to the ganglia of the 
vagus, the petrous ganglion of the glossopharyngeal, and to the hypo- 
glossal. 

Three internal brandies — viz. pharyngeal, laryngeal, and the superior 
cardiac nerve. The pharyngeal runs to the pharynx and unites with 
the branches of the ninth and tenth cranial, forming the pharyngeal 
plexus. . 

The laryngeal branch joins the superior and external laryngeal nerves. 

The superior cardiac nerve descends on the longus colli behind the 
common carotid sheath, and crosses the inferior thyroid artery and recur- 
rent nerve.^ It rises from the upper ganglion, and receives filaments from 
a communicating branch between it and the middle ganglion. On the 
right side it crosses the subclavian, and runs along the innominate artery 
to join the deep cardiac plexus behind the aorta. It receives many 
branches from the vagus and sympathetic. The left descends along the 
left carotid to enter the superficial cardiac plexus in front of the aorta. 

The anterior branches of the superior ganglion pass to the blood-ves- 
sels — viz. to the external carotid and its branches — forming gangliated 
plexuses named lingual, facial, temporal, meningeal, etc. They com- 
municate with the submaxillary and otic ganglia and with the geniculate 
ganglion of the facial nerve {external petrosal nerve). 

Describe the middle cervical ganglion. 

The middle (thyroid ganglion) lies in front of the sixth cervical verte- 
bra, on the inferior thyroid artery. It is connected with the superior 
and inferior ganglia and with the fifth and sixth cervical nerves. It also 
gives off the thyroid branches and middle cardiac nerves. 

The thyroid branches run along the inferior thyroid artery to the 
gland, and join the recurrent and external laryngeal nerves. On the 
artery they connect with the upper cardiac nerve. 

The middle cardiac nerve (deep or great), on the left side, descends 
between the carotid and subclavian arteries to join the deep cardiac 
plexus ; on the right it runs in front of or behind the subclavian artery, 
then along the trachea, to join the deep cardiac plexus. In its course 
it joins the recurrent branch of the vagus and the upper cardiac nerve. 

Describe the inferior cervical ganglion. 

It lies between the transverse process of the seventh cervical vertebra 
and the neck of the first rib, behind the vertebral artery, and commu- 
nicates with the seventh arid eighth cervical nerves. It sends branches 
to the middle cervical and first thoracic ganglion (these branches may be 
derived from the middle cervical ganglion), and some along the vertebral 
artery, forming a plexus. It also sends off the inferior cardiac nerve. 
This descends behind the subclavian artery and along the trachea, and, 
after communicating with the middle cardiac and recurrent nerve, ends 
in the deep cardiac plexus. 



294 the sympathetic nervous system. 

Describe the thoracic portion of the gangliated cord. 

The ganglia lie in a line along the heads of the ribs, beneath the 
pleura and in front of the intercostal vessels. They communicate with 
the spinal nerves. The upper five or six supply the aorta, the vertebrae 
and their ligaments, and enter into the posterior pulmonary plexus. 

The lower six or seven unite to form the splanchnic nerves. 

Name and describe the splanchnic nerves. 

The great splanchnic arises from the fifth or sixth to the ninth or 
tenth, descends obliquely along the spine, and pierces the crus of the 
diaphragm to end in the semilunar ganglion, sending branches to the 
renal plexus and suprarenal capsule. 

The small splanchnic arises from the tenth and eleventh, and, 
piercing the crus, ends in the coeliac plexus, communicating with the 
preceding and the renal plexus. 

The smallest splanchnic arises from the last ganglion, and pierces 
the crus, joining the renal plexus and sending branches to the coeliac 
plexus. 

Describe the lumbar portion of the gangliated cord. 

The lumbar ganglia lie in front of the spine, along the inner side of 
the psoas. They communicate with the ganglia above and below, and 
by two branches with each of the spinal nerves. Branches; : some cross 
the aorta to join the aortic plexus ; some cross the common iliacs and 
enter the hypogastric plexus; others supply the vertebrae and their 
ligaments. 

Describe the sacral portion of the gangliated cord. 

Over the sacrum the ganglia lie internal to the anterior sacral foram- 
ina, sending branches to the ganglia above and below, and two branches 
each to the sacral nerves. The remaining branches join together and 
send filaments, some to enter the pelvic plexus and others to form a 
plexus on the middle sacral artery. The two lowest ganglia on each 
side are joined by a loop over the coccyx, on which is the ganglion 
imp' ir. 

Describe the cardiac and epigastric plexuses of the sympathetic. 

The cardiac plexus lies at the base of the heart, and consists of a 
superficial and a deep part. 

The superficial cardiac plexus lies between the aorta and the 
right pulmonary artery. It is formed by the left superior cardiac nerve 
and the lower cervical cardiac branch of the left vagus, a small ganglion 
(Wrisberg's) being found at their point of union. It forms a great part 
of the right coronary plexus, and sends filaments to the anterior pulmo- 
nary plexus. It receives filaments from the deep cardiac plexus. 

The deep cardiac plexus lies between the trachea and the aorta, 



THE SYMPATHETIC NERVOUS SYSTEM. 295 

above the bifurcation of the pulmonary artery. It receives all the car- 
diac branches of the sympathetic, excepting the left superior cardiac, 
and of the vagus and its recurrent branch, excepting the lower cervical 
cardiac branch of the lei't side. 

From the left side of the plexus branches pass to the superficial car- 
diac- plexus and to the left coronary plexus. From the right, the 
branches in part join those from the superficial plexus to form the right 
coronary plexus; some pass to the left coronary plexus, others to the 
right auricle. Both sides of the plexus furnish filaments to the ante- 
rior pulmonary plexuses. 

The left coronary plexus surrounds the left coronary artery and its 
branches, and supplies the cardiac muscle. The right surrounds the 
right coronary artery in a similar way. The former receives its filaments 
from the deep plexus, the latter from both superficial and deep. 

The epigastric (solar) plexus is placed in front of the aorta and 
crura of the diaphragm, behind the stomach, and between the suprarenal 
bodies. It receives the great splanchnic nerves, and the vagi send 
branches to it. It consists of a collection of nerves and ganglia, and 
its branches accompany the vessels to the principal viscera of the ab- 
domen. 

The largest of its ganglia are the semilunar, one on each side. They 
lie near the suprarenal bodies, in front of the crura, the right one be- 
neath the inferior vena cava. They receive the great splanchnic nerves. 

The branches of the solar plexus form secondary plexuses. 

Describe these secondary plexuses. 

The phrenic plexus, on the artery of the same name, to the dia- 
phragm, supplies also the suprarenal capsules. It joins with branches 
from the phrenic nerve, and at the point of junction on the right side 
is a small ganglion, the diaphragmatic, on the under side of the dia- 
phragm. 

The suprarenal ]ilexus receives branches from the phrenic plexus 
and great splanchnic nerves. At the point where the latter join is a 
ganglion. 

The renal plexus receives filaments from the aortic plexus and the 
small and smallest splanchnics. The branches run along the renal 
artery, and send filaments to the spermatic plexus and to the inferior 
cava. 

The spermatic plexus is derived from the renal and aortic plexuses, 
and runs on the spermatic vessels. In the female {ovarian) it supplies 
the uterus and ovaries. 

The coeliac plexus surrounds the cceliac axis, and divides into the gas- 
tric, hepatic, and splenic plexuses, which accompany the corresponding 
vessels. It receives splanchnic branches; on the left side it receives 
also filaments from the right vagus. 

The gastric plexus receives filaments from the vagi. 



296 THE SYMPATHETIC NERVOUS SYSTEM. 

The hepatic plexus receives branches from the left vagus, and sends 
nerves to the right suprarenal plexus, and forms secondary plexuses, which 
follow the branches of the hepatic artery. 

The splenic plexus is reinforced from the left semilunar ganglion and 
the right vagus. 

All the above plexuses run along with the arteries, and subdivide into 
secondary plexuses, corresponding to the arterial branches, which form 
complex communications with one another. The same applies to the 
following : 

The superior mesenteric plexus is reinforced by a branch from the 
union of the coeliac axis and right vagus. 

The aortic plexus, on the abdominal aorta, is reinforced by filaments 
from the solar plexus and lumbar ganglia, renal plexuses and semilunar 
ganglia. It ends in the hypogastric plexus. 

The inferior mesenteric plexus arises from the preceding, and runs on 
the artery, joining superior mesenteric branches and the pelvic plexus. 

Describe the hypogastric plexus. 

The hypogastric plexus is formed by lateral prolongations from 
the aortic plexus and lumbar ganglia, It lies between the two common 
iliac arteries. Below it bifurcates into the two pelvic plexuses. 

Describe the pelvic plexuses. 

The pelvic plexuses (inferior hypogastric) lie one on each side of the 
rectum, and in the female the vagina. They receive filaments from the 
second, third, and fourth sacral nerves, and where these join the plexus 
small ganglia are developed. The nerves from the plexus supply all the 
pelvic viscera, accompanying the branches of the internal iliac artery and 
forming secondary plexuses. 

Describe these secondary plexuses. 

The hemorrhoidal plexus joins the superior hemorrhoidal branches 
(from the inferior mesenteric plexus) to supply the rectum. 

The vesical plexus contains many spinal nerves, runs with the vesical 
arteries, and sends nerves along the vas deferens. 

The j)rostatic plexus consists of large nerves from the lower part of 
the pelvic plexus, which supply the prostate, seminal vesicles, and cav- 
ernous bodies. These latter are divided into the small and large cavern- 
ous, and join the pudic branches. The small pierce the fibrous coat near 
the root of the penis and end in the erectile tissue. The large (single) 
runs forward on the dorsum, and supplies the corpora spongiosa and 
cavernosa. 

The vaginal plexus runs in the vaginal walls and mucous membrane. 

The uterine plexus sends some branches along the uterine artery, and 
others which directly pierce the cervix and lower part of the body. 
Branches pass also to the ovarian plexus and fundus uteri. 



ORGANS OF SPECIAL SENSE. 297 

ORGANS OF SPECIAL SENSE. 

THE EYE. 
Give a general description of the eyeball. 

The eyeball lies in the fat of the orbit, surrounded by a tunic of fascia, 
the capsule of Tenon. It is composed of segments of two spheres, an 
anterior smaller and a posterior larger, the junction of the sclerotic and 
cornea indicating their limits. It measures 1 inch transversely and ver- 
tically, and somewhat less from before backward. Behind it receives 
the optic nerve, and in front are the eyelids, eyebrows, etc., which com- 
prise the so-called appendages of the eye. 

Describe the appendages of the eye. 

These include the eyebrows, eyelids, conjunctiva, the lachrymal gland 
and sac, and the nasal duct, the last three belonging to the "lachrymal 
apparatus." 

The eyebrows (supercilia) are two prominent tracts of integument above 
the orbit, covered by thick hairs. They are connected with the orbicu- 
laris, corrugator supercilii, and occipito-frontalis muscles. 

The lids (palpebrse) protect the eyeball. Each is composed of thin 
integument, areolar tissue, muscular fibres, the tarsal cartilage and liga- 
ment, Meibomian glands, and conjunctiva; the upper" lid, which is also 
the more movable, contains, in addition, the aponeurosis of the levator 
palpebrse. 

The lids are separated, when opened, by a space, the fissura palpebra- 
rum, and are united at the angles (canthi). The outer canthus is 
sharp, and the inner is more obtuse. At the inner canthus, on each 
lid, is found the lachrymal tubercle, pierced by the punctum lachry- 
male, the upper opening of the lachrymal canal. 

The tarsal cartilages (tarsi) are two plates of dense fibrous tissue, one 
in each lid. Into the anterior surface of the upper the levator palpebrae 
is inserted. Each is attached at the inner angle to the tendo oculi or 
internal tarsal ligament ; at the outer angle to the external tarsal liga- 
ment, which is inserted into the malar bone. 

The tendo oculi or palpebrarum is Y-shaped. The stem is attached to 
the nasal process of the superior maxillary, and each arm to one of the 
tarsal cartilages. 

The palpebral ligament is a fibrous membrane attached to the tarsal 
cartilages and to the corresponding margin of the orbit. 

The Meibomian glands lie on the inner surface of the lids, between 
the tarsal cartilages and the mucous membrane. In the upper lid there 
are about thirty ; in the lower, fewer. 

The lashes (cilia) are short, thick hairs forming a double row on the 
free margin of each lid. Above they are longer and more numerous. 

The conjunctiva is the mucous membrane of the eye. The palpebral 
portion is very thick and vascular, and forms at the inner canthus a fold 



298 ORGANS OF SPECIAL SENSE. 

known as the plica semilunaris. The ocular portion is loosely connected 
to the sclerotic, but over the cornea consists only of the conjunctival 
epithelium. The line of reflection from the lid on to the eyeball is 
called the fornix conjunctivae. 

Near the inner canthus there is also a collection of follicles constituting 
the caruncula lachrymalis, and external to this is the plica semilunaris. 

Describe the lachrymal apparatus* 

It includes the gland, the two canals, the sac, and the nasal duct. 

The gland is about the size and shape of a small almond, and lies in 
a depression in the orbital plate of the frontal bone just inside the ex- 
ternal angular process. Above it is attached to the periosteum, and be- 
low it rests on the eyeball and the upper and outer recti. In front it is 
closely connected to the upper lid and is covered by conjunctiva. Its 
ducts, ten or more in number, run beneath the conjunctiva and open 
separately at the outer part of the fornix. 

The lachrymal canals commence by small orifices, the puncta, on the 
margin of each lid, and empty close together into the sac. The upper 
and longer ascends at first, then runs downward and inward ; the lower 
ones downward, then inward. 

The lachrymal sac is the upper dilated part of the nasal duct, and lies 
in a depression formed by the lachrymal and superior maxillary bones ; 
it is invested by an aponeurosis derived from the tendo oculi, and is 
crossed by the tensor tarsi. 

The nasal duct is contained in a canal formed by the superior maxilla, 
lachrymal and inferior turbinated bones, and runs from the lachrymal 
sac to the inferior meatus. It is lined by a mucous membrane continu- 
ous with the conjunctiva, is narrowest in the middle, and at its lower 
expanded orifice is the valve of Hasner. Its direction is downward, 
backward, and outward. Its epithelium is ciliated. 

Describe the eyeball. 

The eyeball consists of three coats enclosing the refractive media or 
humors. They are the sclerotic and cornea outside, the retina internally, 
and the choroid between them. 

The sclerotic coat is a dense fibrous membrane, white and smooth 
externally, excepting where it receives the insertion of the recti and ob- 
liqui. Internally it is brown, grooved by the ciliary nerves, and united 
by a connective tissue, the lamina fusca, to the choroid beneath. It 
covers the posterior five-sixths of the eyeball. Behind it receives the 
optic nerve at a point just internal to the centre, the fibrous sheath of the 
former being continuous with the sclerotic. Here there is a number of 
small apertures (lamina cribrosa) for the funiculi of the optic nerve, and 
outside of these smaller foramina for the passage of vessels. 

The cornea forms the anterior sixth of the external coat. It is 
transparent and projecting, and nearly circular in shape, the anterior 
surface being convex and the posterior surface concave. 



THE EYE. 299 

Describe the choroid coat. 

The second or intermediate coat is continued into the choroid, pro- 
longed into the iris anteriorly, and forming the ciliary processes. 

It is a chocolate-colored vascular structure lying between the sclerotic 
and retina and investing the posterior live-sixths of the eyeball, blending 
in front with the iris after forming a number of folds, the ciliary processes. 
Behind it is pierced by the optic nerve. It is smooth internally, and is 
connected to the lamina fusca of the sclerotic externally. 

The ciliary processes, seventy or more in number, consist of a circle 
of folds or thickenings of the choroid received into pits in the vitreous 
and suspensory ligament of the lens. They are divided into a larger 
and a smaller set, the former being about ^ inch in length. Their 
inner surface is covered by the layer of hexagonal pigmented cells of 
the retina. 

The choroid is really a plexus of fine blood-vessels. Externally it pre- 
sents a membrane, the lamina suprachoroidea, between which and the 
lamina fusca is a lyniph-space which communicates with the capsule of 
Tenon through apertures in the sclerotic. 

The ciliary muscle is a circular plane of unstriped muscle placed be- 
tween the choroid and sclerotic at its anterior part. It consists of cir- 
cular and radiating fibres. The latter arise near the union of the sclerotic 
and cornea, and are inserted into the choroid opposite the ciliary pro- 
cesses ; the former surround the insertion of the iris. 

The iris gives to the eye its color. It is a thin, contractile, circular 
membrane presenting, at about its centre, a circular aperture, the pupil. 
It is suspended in the aqueous humor behind the cornea and in front of the 
lens. Its circumference is continuous with the choroid and, through the 
ligammtum pectinatum, with the cornea. Its posterior surface is covered 
by dark pigment resembling that of a ripe grape ; hence the term "uvea. ' ' 
The edges of the pupillary orifice are in contact with the lens, the size 
of the pupil varying from -fa to ^ inch across. 

The muscle-fibres are radiating and circular. The latter form a 
sphincter for the pupil; the former constitute the dilator muscle. 

Give the arterial and nervous supply of the iris. 

The arteries are supplied from the long and anterior ciliary. The 
nerves are branches of the lenticular ganglion and the long ciliary from 
the nasal branch of the ophthalmic. They form a plexus around the 
circumference of the iris, and end in the muscular fibres and in a net- 
work on the front of the iris. The nerves to the circular fibres come 
from the motor oculi ; those to the radiating, from the sympathetic. 

Describe the retina. 

It is a delicate nervous membrane on which the image of perceived 
objects is formed. It lies between the choroid and the hyaloid mem- 
brane of the vitreous, and is composed of ten layers. Behind, the optic 
nerve expands into it, and in front it terminates in a dentated margin, 



300 ORGANS OF SPECIAL SENSE. 

the ora serrata, at the outer edge of the ciliary processes. It then sends 
off a thin, non-nervous membrane, the pars ciliaris retinae, to the tips 
of the ciliary processes. The inner surface of the retina presents at its 
centre an elliptical spot about fa inch across, the macula tutea. In the 
centre of this spot is a depression, the fovea centralis, which, on account 
of the extreme thinness of the retina, shows the pigmentary layer of 
the choroid, and hence presents the appearance of a foramen. About 
^ inch to the inner side of the yellow spot is the porus opt km, at which 
point the optic nerve enters, the nervous matter being heaped up here so 
as to form the colliculus. 

What are Miiller's fibres? 

Passing through nearly the entire thickness of the retina, supporting 
its layers and binding them together, are the radiating fibres, or fibres 
of Muller. They form at one extremity the membrana limitans interna, 
and at the other the externa. 

Describe the vitreous body. 

The vitreous is a transparent gelatinous fluid enclosed in a trans- 
parent membrane, the hyaloid, and fills about four-fifths of the eyeball. 
In front it is hollowed out to receive the lens and its capsule, being 
adherent to the back of the latter. In the centre of the vitreous from 
the entrance of the optic nerve to the back of the lens runs a canal. 
It contains fluid, is about T V inch in diameter, and is called the canal 
of Stilling. 

What is the crystalline lens? 

It is a solid transparent biconvex body which lies, enclosed in its 
capsule, in front of the vitreous and behind the iris. The greater con- 
vexity is behind, and the lens measures antero-posteriorly J, transversely 
i, inch. It consists of concentric laminae which are progressively harder 
from without inward. 

The capsule is an elastic, transparent, structureless membrane, in con- 
tact anteriorly with the iris and held in place by the suspoisory liga- 
ment. 

The suspensory ligament is a thin, transparent membrane placed be- 
tween the vitreous humor and the ciliary processes, and presents exter- 
nally a number of folds which receive those of the ciliary processes. It 
is really a part of the hyaloid membrane, which runs forward to the 
front of the margin of the lens. It is also called the zonula of Zinn. 
and is covered externally by the pars ciliaris retinae. Between its back 
part and the lens is a space, the canal of Petit, This canal is bounded 
in front by the suspensory ligament (zonula of Zinn), behind by the 
vitreous, and at its base is the capsule of the lens. 

What is the aqueous humor? 

It is the fluid which fills the space between the suspensory ligament 
and capsule behind and the cornea in front. That part of this space 



THE EAR. 301 

which lies in front of the iris is called the (interior chamber; the part 

behind the iris is the posterior chamber. The latter is really only the 

small interval between the iris, suspensory ligament, and ciliary processes. 

For a more complete description of the eye see Histology of this series. 

THE EAR. 
Describe the ear. 

The ear is divided into the external ear, the middle ear or tympanum, 
and the internal ear or labyrinth. 

Describe the external ear. 

The external ear includes the projecting part, or pinna, and the external 
auditor}/ canal and meatus. The pinna or auricle is concave externally 
and directed somewhat forward, presenting eminences and depressions to 
which various names have been given. Thus, the most external ridge is 
the helix; parallel and internal to this is the antihelix, a ridge which 
divides above to enclose the fossa of the antihelix; between these two 
ridges is the fossa of the helix (fossa scaphoidea) ; in front of the anti- 
helix is a deep depression, the concha, which presents above and in front 
the commencement of the helix ; in front of the concha is a small pro- 
cess, the tragus, which points backward ; and behind this is the anti- 
tragus, a deep notch, the incisura intertragica, separating the two; and, 
lastly, below these is the lobule. 

The pinna consists of a plate of yellow fibro-cartilage covered by skin 
and some adipose tissue. It enters also into the formation of the exter- 
nal meatus, being attached to the external auditory meatus of the tem- 
poral bone. The lobule contains only fat and strong fibrous tissue. 

The external auditory canal is \\ inches long, and runs from the con- 
cha to the membrana tympani. It is directed somewhat forward, and 
presents an eminence in the floor of the osseous part, which makes the 
direction of the canal at first upward, then downward. It is narrowest 
at its middle. Its floor is longer than the roof, on account of the ob- 
lique position of the membrana tympani. It opens externally by means 
of the external auditory meatus. 

Describe the middle ear or tympanum. 

The tympanum is a cavity in the petrous portion of the temporal bone, 
extending from the membrana tympani to the outer wall of the labyrinth. 
Its width varies from ^ to \ inch. It contains the ossicles of the ear, 
with their ligaments and muscles, and certain nerves. It is filled with 
air, and communicates by means of the Eustachian tube with the 
pharj'nx. 

The roof of the tympanum is formed of very thin bone, which sepa- 
rates it from the cranial cavity. The floor is also of bone, and separates 
it from the jugular fossa beneath and the carotid canal in front. The 
outer wall is formed by the membrana tympani and the ring of bone 



302 ORGANS OF SPECIAL SENSE. 

into which this is inserted, and presents, just in front of the bony ring, 
the Glaserian fissure, which lodges the processus gracilis of the malleus 
and transmits some tympanic vessels; at the back part, the iter posterius 
for the entrance of the chorda tympani, and the iter anterius, anteriorly, 
for its exit. The former leads to the aqueductus Fallopii, the latter to 
the canal of Huguier. 

The membrana tympani is a thin membrane inserted into a ring of 
bone at the bottom of the external canal, which is grooved for its recep- 
tion. It is ovoid inform and directed obliquely downward and inward. 
On its inner surface is the handle of the malleus, which extends to a little 
below its centre, covered by mucous membrane where it is attached. This 
process draws the membrane inward, making its outer surface concave and 
its inner convex. Externally, the membrane is covered with skin con- 
tinuous with that of the meatus; internally, with mucous membrane 
continuous with that of the tympanum : and between these two is a 
fibrous layer, some of its fibres radiating from the handle of the malleus, 
others being circular and placed near the circumference. At the antero- 
superior part of the membrane is a notch in the bony ring, the notch of 
Rivini. That part of the membrane occupying it is called the mem- 
brana flaccida. 

The inner wall of the tympanum is vertical and uneven. It presents 
the following : (a) The fenestra oralis, leading into the vestibule, and 
occupied in the recent state by the base of the stapes and its annular 
ligament, {b) Fenestra rotunda, in a conical fossa leading into the coch- 
lea, a rounded eminence, (c) the promontory, separating it from the pre- 
ceding. It is closed, in the recent state, by the membrana tympani se- 
cundaria. This is composed of three layers, and is concave toward the 
tympanum. The middle layer is fibrous, the outer and inner being con- 
tinuous with the lining membrane of the two cavities. The promon- 
tory indicates the first turn of the cochlea, and is grooved for branches 
of the tympanic plexus, {d) The ridge of the aqueductus Falh)>ii. run- 
ning above the fenestra ovalis and descending on the posterior wall, (e) 
The pyramid, a hollow eminence containing the stapedius, the tendon of 
the muscle escaping through a foramen in its summit. A minute canal 
containing the nerve to this muscle runs from the aqueductus Fallopii to 
the cavity of the pyramid. 

The posterior wall of the tympanum presents above one large and 
several small apertures leading to the mastoid cells. 

The anterior extremity opens into two canals separated by a process of 
bone, the processus cochleariformis. The upper of these canals is the 
smaller and transmits the tensor tympani ; the lower contains the Eusta- 
chian tube, an osseocartilaginous passage 1$ inches long, leading to the 
pharynx. Both of these canals run in a direction downward, forward, 
and inward. 

The osseous part of the Eustachian tube is ] an inch long, and to its 
lower end is attached the triangular piece of fibro-cartilage forming the 
remainder of the tube. The edges of the cartilage are not in contact, 



THE EAR. 303 

but are joined by fibrous tissue. The tube is wide at its lower extremity, 
and opens at the upper and lateral part of the pharynx, above the hard 
palate and behind the lower turbinated bone. It is lined by epithelium 
continuous with that of the pharynx. 

Describe the ossicula. 

These are three small movable bones, named the malleus, incus, and 
stapes. The first is attached to the membrana tympani ; the second is 
between the other two ; the last-named is attached to the fenestra ovalis. 

The malleus (a hammer) consists of a head, neck, and three processes 
— viz. the processus gracilis, the processus brews, and the manubrium. 
The head articulates with the incus. The neck is below it, and rests on 
a prominence which is connected with the three processes. The ma- 
nubrium tapers to its extremity, which is flattened, and it is connected 
with the membrana tympani. The tensor tympani is attached to its 
inner side near its upper end, and from its root springs the processus 
brevis. The j^'oce-ssus gracilis is long and slender, and is connected by 
bone and fibrous tissue with the Glaserian fissure. 

The incus (an anvil) has a body and two processes. The body pre- 
sents a saddle-shaped articular surface for the malleus ; the short process 
is conical, looks backward, and is attached to the opening which leads to 
the mastoid cells ; the long process descends behind the manubrium of 
the malleus, to end in the os orbiculare, or lenticular process, which articu- 
lates with the head of the stapes. 

The stapes (a stirrup) presents a head, which articulates with the os 
orbiculare; a, neck, to which is attached the stapedius muscle ; and two 
crura, diverging from the neck, and connected at their extremities by the 
base, which fills up the fenestra ovalis. 

Describe the ligaments of the ossicula. 

The articulations between the several bones are provided with sjmovial 
membranes ; their surfaces are covered with cartilage and are connected 
by capsular ligaments. The following ligaments connect the bones with 
the walls of the tympanum : 

The anterior ligament of the malleus is attached to the neck of the 
malleus at one end, and at the other to the anterior wall of the tympanum 
close to the Glaserian fissure, and its suspensory ligament runs from the 
roof of the tympanum to the head of the bone. An external ligament 
runs from the notch of Rivini to the body and lesser process, and the 
accessory anterior ligament is the thickened front portion of the sheath 
of the tensor tympani. which runs from the anterior wall to the manu- 
brium and neck. An inferior ligament runs from the end of the handle 
to the outer wall of the tympanum. 

The base of the stapes is fixed to the margin of the fenestra ovalis by 
an annular ligament. 

The incus is provided with a posterior ligament, running from the 



304 ORGANS OF SPECIAL SENSE. 

short process to the posterior wall, and a suspensory ligament, from the 
roof of the tympanum to the upper part of the bone near its articulation 
with the malleus. 

Describe the muscles, mucous membrane, vessels, and nerves of 
the tympanum. 

The tensor tympani runs in the canal previously mentioned. Aris- 
ing from the under surface of the petrous portion, the cartilage of the 
Eustachian tube, and the margins of its own canal, its tendon is reflected 
over the processus cochleariformis and is inserted into the handle of the 
malleus near its root. It pulls on the malleus, thus drawing inward and 
making tense the membrana tympani. Its nerve comes from the otic 
ganglion. 

The stapedius arises from the sides of its containing cavity within 
the pyramid, and, emerging from the apex, is inserted into the neck of 
the stapes. It draws the head of the stapes backward, thus pressing 
the base against the fenestra ovalis and compressing the contents of the 
vestibule. Its nerve is the tympanic branch of the facial. 

The mucous membrane of the tympanum is pale and thin and its 
epithelium ciliated. It invests the contents of the cavity, the inner sur- 
face of the membrana, and covers the fenestra rotunda. It is continuous 
with that of the mastoid cells, Eustachian tube, and pharynx. 

The tympanic arteries come from the internal maxillary, the stylo- 
mastoid branch of the posterior auricular, the petrosal branch of the 
middle meningeal, the Eustachian branch of the ascending pharyngeal, 
and from the internal carotid. The veins reach the internal jugular by 
means of the middle meningeal and pharyngeal veins. 

The nerves of the tympanum are the muscular, already men- 
tioned; the nerves to the mucous membrane from the tympanic plexus; 
the communicating, viz. between Jacobson's nerve, the sympathetic, and 
branches of the geniculate ganglion of the seventh; and the chorda 
tympani. 

Jacobson's nerve (tympanic branch of the ninth) enters the tympanum 
in the floor and passes to the promontory. It forms the tympanic 
plexus, from which are supplied the fenestras, Eustachian tube, and 
lining membrane, and sends oft* two communicating branches : one to 
the carotid plexus, one to the great superficial petrosal. It then receives 
a filament from the geniculate ganglion of the facial, and proceeds to join 
the otic ganglion as the lesser superficial petrosal nerve. 

The chorda tympani arises from the facial near the stylo-mastoid fora- 
men, enters at the base of the pyramid, crosses the tympanum between - 
the long process of incus and handle of malleus, and runs through the 
iter chordae anterius to the canal of Huguier. 

Describe the internal ear. 

This is the essential part of the hearing apparatus, since here the 
auditory nerve is distributed. It is contained in a cavity in the petrous 



THE EAR. 305 

bone, and is made up of the osseous labyrinth and the membranous 
labyrinth. 

Describe the osseous labyrinth. 

The osseous labyrinth contains the mcmhranous labyrinth, and is 
divided into three parts, the vestibule, semicircular canals, and cochlea. 
It communicates in the dry state with the tympanum by means of the 
fenestra?. Between the osseous and membranous labyrinth is a space 
occupied by a clear fluid, the perilymph, and within the membranous 
labyrinth is the endolymph. 

The vestibule is the central cavity lying between the cochlea in front 
and the semicircular canal behind, the tympanum being external. Its 
outer or tympanic wall presents the fenestra ovalis. 

Its inner wall has in front a depression, the fovea hemisplierica, pierced 
by several minute holes for the auditory filaments, and, behind this, a 
ridge, the crista vestibuli. Behind this ridge is the opening of the aque- 
ductus vestibuli. In the roof is a depression, the fovea hemi-elliptica. 

Behind, the vestibule presents five foramina leading into the semicir- 
cular canals, and in front a larger foramen leading into the scala vestib- 
uli of the cochlea. 

The semicircular canals are three bony tubes of unequal length 
lying above and behind the vestibule, each forming about two-thirds of a 
circle. Their general diameter is 2V inch, but at one end is a dilatation, 
the ampulla, £5 inch in diameter. They empty into the vestibule by five 
apertures, in one of which two tubes join. 

The superior is vertical and is set transversely, forming an eminence 
seen on the upper surface of the petrous bone. The ampulla of this 
tube opens into the upper part of the vestibule, the other end opening by 
a foramen into the back part, in common with the posterior canal. 

The posterior is also vertical, but is set antero-posteriorly and is longer 
than the others, its ampulla being at the postero-inierior part of the vesti- 
bule, the other extremity joining with the preceding canal, as described. 

The external is horizontal and the shortest, its ampulla being at the 
outer part, above the fenestra ovalis, and the other end at the upper and 
back part of the vestibule. 

The cochlea resembles a snail-shell. Its apex looks forward and out- 
ward, and its base toward the internal auditory meatus. Within is a 
centre-piece, the modiolus or columella, around which the canal runs 
spirally for two and a half turns. 

Within the canal, and attached to the modiolus, is the lamina spiralis. 
This plate of bone partially divides the spiral canal into two compart- 
ments or scalge, the division being completed by a membrane [see below) 
which reaches the outer wall of the cochlea. The upper scala is known 
as the scala vestibuli ; the lower is the scala tympani. 

The modiolus or columella, the centre-piece of the cochlea, runs from 
base to apex. It is conical in form, the base corresponding to that of 
the cochlea, and is pierced by foramina for the cochlear branches of the 
20— A. 



306 ORGANS OF SPECIAL SENSE. 

auditory nerve and for the vessels which pass to the lamina and spiral 
canal. One of these, larger than the rest, is the opening of the canalix 
modioli centralis. Diminishing gradually in size, the modiolus termi- 
nates above in a bony process, the infundibulum, which blends with the 
cupola or last half turn of the spiral canal. Here the two scalae commu- 
nicate by a small opening, the helicotrema. Around the modiolus, along 
the attachment of the lamina spiralis, is the spiral canal of the modio- 
lus, containing a gangliated portion of the cochlear nerve, the ganglion 
spirale. 

The spiral canal is l£ inches long and r V inch m diameter at its widest 
part, which is below. The scala vestibuli communicates with the vesti- 
oule by the foramen above mentioned, and a part of it, marked off by a 
membrane, is called the scala media {see below). The scala tympani 
commences at the fenestra rotunda, and close to its commencement is the 
opening of the aquedv.ctus cochlea?., by which it communicates with the 
subarachnoid space, and in which there is transmitted a small vein to the 
internal jugular. The spiral lamina ends above in a hook-like process, 
the hamulus, which partly bounds the helicotrema. 

Describe the membranous labyrinth. 

The membranous labyrinth is contained within the osseous labyrinth, 
having a similar form, though smaller and separated from it by the peri- 
lymph. It contains the endolymph and receives the distribution of the 
auditory nerve. In the vestibule it consists of the utricle and the saccule. 

The utricle is in the upper and back part, its cavity communicating 
by five apertures with the membranous semicircular canals. It is in con- 
tact with the fovea hemi-elliptica. 

The saccule is in the fovea hemispherical and communicates with the 
utricle by means of a small tube which passes into the aqueductus vesti- 
buli, and there joins a canal [saccus endoh/mphaticus), which canal is 
prolonged from the utricle and ends in a blind extremity ; and with the 
scala media by means of the canalis reuniens. 

The membranous semicircular canals are similar in shape to, but are only 
from one-fifth to one-third the diameter of, the bony canals ; the ampullae, 
however, are relatively large. Two small masses of calcium carbonate 
are found in the utricle and saccule. They are called the otoliths. 

In the cochlea the membranous labyrinth is represented by the scala 
media and the parts therein, which are formed as follows : 

Along the edge of the spiral lamina the periosteum on its upper sur- 
face is raised up like a C to form* the limbus laminae spiralis. Thus 
there is a groove (the sulcus spiralis), the upper and lower lips of this 
sulcus being called respectively the labium vestibulare and tympauicum. 
From the latter the membrana basifaris extends to the outer wall, along 
the latter attachment forming the ligamentum spirale. Above the lim- 
bus to the outer wall stretches another membrane, Reissner'Si The 
space below the osseous lamina and the membrana basilaris is the scala 
tympani ; above the membrane of Reissner is the scala vestibuli ; and that 



THE NOSE. 307 

space bounded by the two membranes and the outer wall of the cochlea is 
known as the scala media, or canal of the cochlea, which ends at the apex 
of the cochlea in a blind pointed extremity, and opens below into the 
saccule, as described above. Between the two membranes mentioned a 
third stretches across in the scala media to the outer wall. This is called 
the membrane of Corti, or membrana tectoria. Between the membrana 
basilaris and the last-named membrane is a space which contains the 
organ of Corti. 

The organ of Corti lies on the basilar membrane. The central part 
is composed of two rows of peculiarly-shaped cells called the rods of 
Corti, outer and inner. These rods meet above by their extremities, and 
enclose an angular tunnel between them and the basilar membrane, the 
zona arcuata. The inner rods run close to the labium tympanicum, and 
along their inner side is a series of epithelioid cells continuous with the 
cubical epithelium of the sulcus spiralis. These present a row of short, 
stiff hairs, forming a sort of brush. External to the outer rods are 
several rows of similar cells. These are called the outer and inner hair- 
cells. 

The reticular lamina is a delicate structure composed of small seg- 
ments called phalanges arranged side by side and separated by holes, 
through which the hairs of the outer hair-cells project. The whole 
organ thus described is covered by the membrane of Corti (membrana 
tectoria). 

Give the arterial and nervous supply. 

The arteries of the internal ear are the auditory branch of the basilar, 
the stylo-mastoid branch of the posterior auricular, and branches occa- 
sionally from the occipital. The first named divides into a cochlear and 
a vestibular branch. 

The auditory nerve divides at the bottom of the internal auditory 
meatus into a superior and an inferior branch. The former divides into 
branches, which are distributed to the utricle and to the ampullae of the 
superior and external semicircular canals ; the latter sends branches to 
the saccule, to the ampulla of the posterior canal, and to the cochlea. 

The cochlear branch sends its filaments through the canals of the 
modiolus, and these form the ganglion spirale. This ganglion sends 
other filaments to the sulcus spirale and organ of Corti. 

THE NOSE. 
Describe the nose. 

The nose is the organ of smell, and consists of an external part, the 
nose, and an interval, the nasal fossae. 

The nose is triangular, and is formed by the nasal bones and nasal pro- 
cesses of the superior maxillary bones, and of five cartilages — viz. the two 
upper and the two lower lateral cartilages, and the cartilage of the sep- 
tum. The two openings, the anterior nares, are directed downward, and 
just inside of them are some short, stiff hairs, the vibrissae. The bones 



308 ORGANS OF SPECIAL SENSE. 

and cartilages are covered by skin on the outer side and by mucous mem- 
brane on the inner. Between the anterior nares is a fold of skin, the 
columna nasi, which continues the septum. The two lateral parts join 
in front to form the dorsum, and this ends below in the rounded lobe of 
the nose. 

The upper literal cartilages Me one on each side, below the nasal bones, 
and are triangular in form. The anterior margin joins its fellow above 
and the edge of the cartilage of the septum below. The inferior edge 
joins the lower lateral cartilage by means of fibrous tissue, and the pos- 
terior edge the nasal and superior maxillary bones. 

The lower lateral cartilages are thin, and arc curved so as to form the 
front and both walls of the nostrils. Behind it is attached to the supe- 
rior maxilla, above to the upper cartilage. Between it and the former 
several smaller cartilages may be seen. It also joins a small part of the 
cartilage of the septum. In front it joins its fellow to form the tip of 
the nose. 

The cartilage of the septum is quadrilateral, and thinner at the centre 
than at its borders. It forms the anterior part of the septum, and is 
joined superiorly to the nasal bones, and to the upper and lower lateral 
cartilages by its anterior margin. Its posterior margin is attached to the 
front of the perpendicular plate of the ethmoid, and its lower margin to 
a groove on the vomer and the ridge between the superior maxillae. 

The arteries are the lateralis nasi, artery of the septum from the supe- 
rior coronary, infraorbital, and nasal branch of the ophthalmic. 

The veins end in the facial and ophthalmic. 

The nerves are from the facial, infraorbital, infratrochlear, and nasal 
branch of the ophthalmic. 

Describe the nasal fossae. 

For the osseous part, see Bones. These fossae open in front by the an- 
terior nares, and into the pharynx behind by the posterior nares. The 
mucous membrane is called the pituitary or Schneidcrian membrane, and 
is attached directly to the periosteum or perichondrium. It is continu- 
ous with that of the pharynx, conjunctiva, tympanum, and mastoid cells, 
antrum of Highmore, and with that of the different canals which con- 
nect these parts. 

The epithelium is squamous near the nostril, columnar where the olfac- 
tory nerves are distributed, and columnar and ciliated elsewhere. 

The nasal fossae in the recent state present a different appearance from 
that seen in the skeleton. They are narrowed, and their component 
parts appear thicker, the turbinated bones being very prominent. The 
apertures of the various foramina are narrowed, or even closed, by the 
lining membrane. 

The arteries of the nasal fossae are the ethmoidal, the small meningeal, 
spheno-palatine, and alveolar. 

The veins empty into the ophthalmic and facial, and through the for- 
amen caecum communicate with the cranial sinuses. 



THE TONGUE. 309 

The nerves are the olfactory filaments distributed to the upper third 
of the septum and the surfaces of the superior and middle turbinated 
bone (these filaments do not reach the superior or middle meatus), the 
nasal branch of the ophthalmic, the anterior dental of the superior max- 
illary, and the Vidian, naso-palatine, and anterior palatine. 

THE TONGUE. 
Describe the tongue. 

The tongue is composed of muscular substance covered by mucous 
membrane. Behind it is attached to the hyoid bone, and below by 
means of the genioglossus to the lower jaw. The mucous membrane is 
continuous with that of the gums, and forms on the middle line of the 
under surface a fold, the frcvnum Unguoe. Along the middle line of the 
dorsum is a depression, the raphe, which ends in the foramen ccecum, 1 
inch from the base. At its base three folds of mucous membrane, the 
glosso-epiglottic ligaments, connect it with the epiglottis. 

The anterior two-thirds of the dorsum is covered with papillce, as well 
as the tip and borders. These are of three kinds, circumvallate, fungi- 
form, and conical, and are covered by minute secondary papillae. 

The circumvallate (papilla? maxima?), eight to ten in number, run from 
the foramen ca?curu in two lines forward and outward, making a V. 
Each papilla lies in a depression which is surrounded, in turn, by an 
elevated ring. 

The fungiform (media?) are smaller and more numerous. They occupy 
the middle and front part of the dorsum, and occur at the apex and near 
the borders. 

The conical po 'pillce (minima?) are the smallest and most numerous, 
and are found all over the dorsum. They run in lines which diverge 
from the raphe obliquely behind, nearly transversely in front. 

The secondary papilla? send off fine processes, which give the appear- 
ance called filiform. 

The glands of the mucous membrane are of two kinds, mucous and 
serous glands. 

A quantity of lymphoid tissue, is found between the epiglottis and 
papilla? maxima?, collected into masses, the follicles. The epithelium is 
stratified. 

The tongue is divided by a fibrous septum into two symmetrical lateral 
halves : this septum is connected to the Iryoid bone by the so-called hypo- 
glossal membrane, which receives some of the fibres of the genio-hyo- 
glossus muscle. 

The tongue has extrinsic and intrinsic muscular fibres. The former 
include the hyoglossus, genioglossus, styloglossus, palatoglossus, and part 
of the superior constrictor. The intrinsic muscles are the various parts 
of the lingualis. These parts are the superior and inferior longitudinal, 
vertical, and transverse. 



310 ORGANS OF RESPIRATION. 

The arteries are the lingual and branches of the ascending pharyngeal 
and facial. The veins join the internal jugular. 

The nerves are four in number : the lingual branch of the fifth (gus- 
tatory), to its anterior two-thirds; the lingual branch of the glosso- 
pharyngeal, to the base and papillae maximae ; the hypoglossal, to the 
muscles; and the chorda tympani, to the lingualis. It also receives sym- 
pathetic branches. 

The glossopharyngeal confers taste ; the gustatory, common sensation ; 
and the hypoglossal, motion ; also the facial, by means of fibres from the 
chorda tympani. 

SPLANCHNOLOGY. 

Organs of Respiration. 

THE LARYNX. 
Give a general description of the larynx. 

The larynx is the organ of voice, and is placed at the upper and fore 
part of the neck, between the trachea and base of the tongue. It has 
on each side of it the great vessels, and behind it the pharynx. In front 
are the cervical fascia mesially and the upper end of the thyroid gland, 
and on each side the sterno-hyoid and thyroid and the thyro-hyoid mus- 
cles. It consists of various cartilages held together by ligaments, and is 
lined internally by mucous membrane. 

What are the cartilages? 

The cartilages are nine : three pairs, the arytenoid, cornicula laryngis, 
and cuneiform ; and three single, the thyroid, cricoid, and epiglottis. 

Describe the thyroid cartilage. 

It is the largest, and consists of two lateral parts or alae uniting in 
front to form the projection of the pomum Adami. This is subcutaneous, 
more distinct above and in the male. Each ala is quadrilateral, and pre- 
sents externally a tubercle from which a ridge descends obliquely for- 
ward. This ridge gives attachment to the sterno-thyroid and thyro-hyoid. 
and the surface behind it to the inferior constrictor muscle. Internally 
it is smooth, and in the angle the epiglottis, true and false vocal cords. 
and the thyroarytenoid and thyro-epiglottic muscles are attached. The 
upper border is concavo-convex, and in front is notched over the pomum 
Adami, giving attachment throughout to the thyro-hyoid membrane. 
The lower border is joined to the cricoid cartilage by the crico-thyroid 
membrane. The posterior borders end in the upper and lower cornun : 
to the upper are attached the lateral thyro-hyoid ligaments, and the 
lower, which are shorter and thicker, present internally a facet for 
articulation with the cricoid cartilage. The stylo- and paiato-pharyngei 
are attached also to the posterior border. 



THE LARYNX. 311 

Describe the cricoid cartilage. 

It resembles a signet ring, is narrow in front, and gives attachment to 
the crico-thyroid muscle, and behind it to some of the fibres of the 
inferior constrictor. It is broad behind, with a median ridge for the 
oesophagus, separating two hollows for the crico-arytenoideus posticus, 
and presents at about the middle of the lateral surface a prominence 
on each side which articulates with the corresponding inferior cornu of. 
the thyroid cartilage. The lower border is joined to the upper ring of 
the trachea; the upper gives attachment in front and laterally to the 
crico-thyroid membrane and the lateral crico-arytenoideus muscle. Be- 
hind, at each end of its upper border, is an oval surface for the corre- 
sponding arytenoid cartilage, with a notch between. 

Describe the arytenoid cartilages. 

They are pyramidal in form, and rest by their bases on the highest part 
of the upper border of the cricoid cartilage behind, their curved apices 
approximating. To the posterior surface is attached the arytenoideus ; 
to the anterior, the thyro-arytenoideus and the false vocal cord ; and the 
internal is covered by mucous membrane. The apex is curved backward 
and inward, and surmounted by the corniculum laryngis. The base pre- 
sents a concave surface to articulate with the cricoid cartilage, and to its 
external angle {muscular process) are attached the lateral and posterior 
crico-arytenoidei, and to the anterior angle [vocal process) the true vocal 
cord. 

The cornicula lai-yngis (cartilages of Santorini) are two small, conical, 
yellowish bodies which prolong the apices of the arytenoid cartilages 
backward and inward. 

The cuneiform cartilages (Wrisberg's) are two small, yellow, elongated 
bodies lying one in each fold of the mucous membrane which stretches 
between the arytenoid cartilage and the epiglottis. 

The epiglottis is a fibro-cartilaginous lamella, shaped like a leaf, lying 
behind the tongue and in front of the upper orifice of the larynx. Above 
it is broad, below narrow and prolonged to the notch above the pomum 
Adami by the thyro-epiglottic ligament, or, rather, to the angular inter- 
val just below the notch, and is attached to the body of the hyoid bone 
by the hyo-epiglottic ligament. Laterally are attached the aryteno-epi- 
glottic folds. The anterior surface is connected with the tongue by the 
lateral and median glosso- epiglottic folds. The posterior surface is con- 
cave transversely, convex longitudinally. 

Describe the ligaments of the larynx. 

These are extrinsic and intrinsic. The former connect it to the hyoid 
bone ; the latter connect its parts together. 

The extrinsic are the middle thyro-hyoid ligament, the two lateral 
thyro-hyoid ligaments, and the hyo-epiglottic ligament. 

The middle thyro-hyoid ligament is a fibro-elastic structure attached 
to the entire border of the notch of the thvroid cartilage and to the 



312 



ORGANS OF RESPIRATION. 



upper border of the posterior surface of the body of the hyoid bone. 
The lateral thyro-hyoid ligaments run between the upper cornua of the 
thyroid and the greater cornua of the hyoid bone. They sometimes 
enclose the cartilago triticea, a small cartilaginous nodule occasionally 
ossified. The hyo-epiglottic ligament runs from the front of the epiglot- 
tis near its apex to the upper border of the body of the hyoid bone. 

Describe the intrinsic ligaments. 

The ligaments connecting the thyroid and cricoid cartilages are the 
crico-thyroid ligament, the capsular ligaments, and the synovial mem- 
branes. The crico-thyroid ligament is of yellow elastic tissue, trian- 
gular, and consists of a mesial thicker portion connecting the adjacent 
borders of the two cartilages, and two lateral portions running from the 
upper border of the cricoid to be continuous with the inferior thyroary- 
tenoid ligaments [true vocal cords). In front this ligament is partly 
covered by the crico-thyroid muscles on each side, and in the subcuta- 
neous interval there is a sort of plexus from the junction of the two 
crico-thyroid arteries. The lower cornua of the thyroid are connected 
with the sides of the cricoid by two ligamentous capsules each lined by 
a synovial membrane. 

The cricoid and arytenoid cartilages are connected by loose capsular 
ligaments lined by synovial membranes, and by a posterior crico-aryte- 
noid ligament running from the cricoid to the inner and back part of the 
base of the arytenoid. 

The ligaments of the epiglottis are the hyo-epiglottic, the three glosso- 
epiglottic ligaments (mucous membrane), and the thyro-epiglottic. The 
latter is a long and slender cord between the apex of the epiglottis and 
the angle of the thyroid just below the notch. 

Describe the interior of the larynx. 

The cavity of the larynx is divided into an upper and a lower part by 
the rima glottidis. The upper opens into the pharynx by the upper 
aperture of the larynx, between which and the rima glottidis are the 
ventricles and their saccules and the false vocal cords. The lower aper- 
ture is continuous with the trachea. 

The superior aperture is cordiform in shape, widest in front and nar- 
row behind. In front it is bounded by the epiglottis, behind by the 
arytenoid cartilages (together with the fold of mucous membrane between 
them) and cornicula, and laterally by the aryteno-epiglottic folds. 

The rima glottidis is the space between the true vocal cords and the 
bases of the arytenoid cartilages. It is somewhat less than 1 inch lorn*, 
and, according to its degree of dilatation, from i to £ an inch wide. In 
easy respiration its form is triangular with the base posterior, and when 
fully dilated it is lozenge-shaped. 

What are the superior or false vocal cords ? 
They are two mucous folds, each enclosing the corresponding superior 



THE LARYNX. 313 

thyroarytenoid ligament. This latter is a thin Land running between the 
angle of the thyroid and the anterior surface of the arytenoid cartilage. 

What are the inferior or true vocal cords ? 

They are two strong bands, the inferior thyro-arytenoid ligaments, cov- 
ered by mucous membrane and attached to the depression between the 
alae of the thyroid cartilage in front and the anterior angle of the base 
{ vocal process) of the arytenoid cartilages behind. Below, each is contin- 
uous with the lateral part of the crico-thyroid ligament or membrane. 
Part of the thyro-arytenoidei is external and parallel to them. 

Describe the ventricles of the larynx. 

The ventricles of the larynx lie one on each side, between the upper 
and lower vocal cords, bounded externally by the thyro-arytenoidei. At 
the front a narrow opening leads into a blind pouch, the laryngeal saccule. 

What is the saccule? 

The sacculus laryngis is a space on each side, between the false vocal 
cord and the inner surface of the thyroid cartilage, reaching upward as 
high as the upper border of that cartilage, and its mucous membrane 
presents the orifices of sixty or seventy glands. This space has a fibrous 
capsule. Its laryngeal surface is covered by the inferior aryteno-epiglot- 
tic muscle, orcompressor sacculi laryngis, and its external surface by the 
thyro-arytenoideus and thyroepiglottic muscles. 

Name and describe the intrinsic muscles of the larynx. 

They are the following : 

(1) The crico-thyroid arises from the front part and sides of the cricoid 
cartilage, and is inserted into the lower border of the thyroid cartilage 
and the front of its lower cornu. Between the two muscles is the crico- 
thyroid membrane. The action of the two muscles is to approximate 
the cricoid to the thyroid and thus tense the vocal cords. The nerve- 
supply is from the superior laryngeal. 

(2) The thyro-arytenoid is divided into two parts, outer and inner. It 
arises in front from the angle of the thyroid at its lower part, and its 
inner part is inserted into the vocal process and outer surface of the 
arytenoid cartilage ; its outer part, into the outer border and muscular 
process of the same cartilage, above the internal part. The internal 
part is adherent and parallel to the true vocal cord ; the outer is external 
to the sacculus laryngis. Their action is to advance the arytenoid carti- 
lages and thus relax the vocal cords. The nerve comes from the inferior 
laryngeal. 

(3) The thyroepiglottic muscle arises from the inner surface of the 
thyroid cartilage, close to the angle, and is inserted into the sacculus laryn- 
gis, epiglottis, and aryteno-epiglottic fold. It is really a part of the 
preceding muscle. Its action is to depress the epiglottis and compress 
the sacculus laryngis. Its nerve is from the inferior laryngeal. 

(4) The superior aryteno-epiglottic muscle arises from the apex of the 



314 ORGANS OF RESPIRATION. 

arytenoid, and is enclosed by the aryteno-epiglottic mucous folds bearing 
the same name. Additional fibres from each muscle decussate. These 
fibres extend from the apex of one cartilage to the muscular process of 
the other, and lie behind and on the arytenoideus. Its action is to dimin- 
ish the size of the superior aperture of the larynx during deglutition. 
Its nerve is from the inferior laryngeal. 

(5) The inferior aryteno-epiglottie muscle arises from the arytenoid 
cartilage, just above the false cord, and is inserted into the upper and 
inner part of the epiglottis. Its other name, compressor sacculi laryngis, 
indicates its action. It is really a part of the thyro-arytenoid muscle. 
Its nerve is from the inferior laryngeal. 

(6) The crico-arytenoideus posticus arises from the back of the cricoid 
cartilage, and is inserted into the muscular process of the arytenoid. 
Its action is to rotate the corresponding arytenoid outward and thus to 
widen the glottis. The nerve is from the inferior laryngeal. 

(7) The crico-arytenoideus lateralis arises from the upper border of the 
cricoid cartilage, and is inserted into the muscular process of the arytenoid 
cartilage. Its action is to rotate the corresponding cartilage inward, thus 
narrowing the glottis. The nerve is from the inferior laryngeal. 

(8) The arytenoideus is attached to the posterior surface of each aryte- 
noid cartilage. Its fibres run transversely. Its action is to close the 
back part of the glottis by means of the approximation of the arytenoid 
cartilages. Its nerve-supply is from both superior and inferior laryngeal 
nerves. 

THE TRACHEA. 

Describe the trachea. 

The trachea is a membrano-cartilaginous tube, flattened behind, con- 
tinuous above with the larynx, and below dividing into the two bronchi. 
Its upper limit is at the sixth cervical, its lower at the disk between the 
fourth and fifth dorsal vertebras, and it measures about 4£ inches in 
length; transversely, f to 1 inch. 

What are its relations? 

In front: in the neck, the isthmus of the thyroid, the sterno-hyoid 
and thyroid and the cervical fascia between them, the arteria thyroidea 
ima. the inferior thyroid veins, and the communicating branches between 
the anterior jugulars; in the thorax, the manubrium sterni, thymic re- 
mains, the left innominate vein, arch of the aorta, innominate and 
left carotid vessels, and the deep cardiac plexus. Behind is the oesoph- 
agus. Laterally: in the neck, the common carotids, the lateral lobes 
of the thyroid, the inferior thyroid arteries, and the recurrent nerves ; 
in the cheM, the pleura of each side and the vagus. 

Describe the bronchi. 

The bronchi enter the root of the corresponding lung. The right is 
the shorter, wider, and more horizontal, and enters the lung opposite 



THE THYROID AND THYMUS (J LANDS, ETC. 315 

the fifth dorsal vertebra, the larger azygos vein arching over it from be- 
hind, the right pulmonary artery being below and then in front of it. The 
left bronchus is about 2 inches long, and enters the lung opposite the 
sixtli dorsal vertebra. It passes under the arch of the aorta and crosses 
in front of the oesophagus, thoracic duct, and descending aorta. The 
left pulmonary artery lies at first above, then in front of it. 

What is the structure of the trachea ? 

The trachea consists of sixteen to twenty incomplete cartilaginous 
rings connected by a fibrous membrane. Their free ends, which are 
directed posteriorly, are united similarly and by plain muscular tissue. 

THE THYROID AND THYMUS GLANDS. 
Describe the thyroid gland. 

The thyroid gland is a highly vascular body situated at the upper part 
of the trachea, and consists of two lateral lobes connected by the isthmus. 
The lateral lobes are placed one on each side of the trachea. 

In front it is convex and covered by the sterno-hyoid and thyroid and 
omo-hyoid muscles ; laterally, also convex, it touches the common carotid 
sheath; behind it is concave and rests on the larynx and trachea. 

The weight of this body is from 1 to 2 ounces, its colorbrownish-red, 
and each lobe is 2 inches long by li inches wide. There is sometimes a 
third and accessory smaller lobe, called the pyramid. 

Describe the thymus gland. 

The thymus is a temporary organ, attaining its greatest size at the end 
of the second year, and gradually dwindling thereafter to a mere trace. 
At its full growth it lies in the neck and superior mediastinum, and con- 
sists of two lobes extending behind the sternum from the level of the 
fourth cartilage below to the thyroid gland above. 

In front are the sternum, sterno-, hyoid and tlryroid ; behind are the 
pericardium, the great vessels, and the trachea. For the structure of 
these bodies see Histology of this series. 

PLEURiE AND MEDIASTINUM. 
Describe the pleurae. 

The pleurae are two separate serous sacs which invest each lung to its 
root and are reflected on to the thoracic walls and pericardium. The first 
portion is the visceral layer, or pleura pulmonalis; the second is the 
parietal layer, or pleura costalis. 

The two pleurae are distinct from each other, and do not meet in the 
median line except behind the second piece of the sternum. At the 
root of the lung the visceral and parietal layer of the same side are con- 
tinuous, and at the lower part of the root a fold, the ligamentum latum 
pulmonis, runs down to the diaphragm. 



316 



ORGANS OF RESPIRATION. 



What is the mediastinum, and how is it subdivided? 

The mediastinum is the space between the two pleural sacs, and ex- 
tends antero-posteriorly from the sternum to the spine ; it is divided into — 
a superior mediastinum, above the upper level of the pericardium; the 
anterior, in front of the pericardium: the middle, containing the peri- 
cardium ; and the posterior mediastinum, behind the pericardium. 

Describe each of these subdivisions. 

The superior mediastinum is bounded by the manubrium sterni in 
front, the upper four dorsal vertebrae behind, and below by a plane pass- 
ing from the lower border of the manubrium to the lower part of the 
fourth dorsal vertebra. It contains the lower part of the sterno-hyoid 
and thyroid and longus colli muscles, the transverse aorta, innominate, 
left carotid, and subclavian arteries, the superior cava (upper part), the 
two innominate and the left superior intercostal veins, the vagus, car- 
diac, phrenic, and left recurrent nerves, trachea, oesophagus, thoracic 
duct, thymic remains, and lymphatics. 

The anterior mediastinum is bounded by the sternum and the peri- 
cardium before and behind, by the pleurae laterally. It runs toward the 
left, is broader below than above, and contains the origins of the tri- 
angularis sterni, the left internal mammary vessels, some areolar tissue 
containing lymphatics, and the anterior mediastinal glands. 

The middle mediastinum contains the heart and pericardium, ascend- 
ing aorta, superior cava (lower part), bifurcation of trachea, pulmonary 
vessels, the phrenic nerves, and the arch of the vena azygos. 

The posterior mediastinum is behind the pericardium and roots of the 
lungs, and in front of the lower eight dorsal vertebrae, the pleurae bound- 
ing it on each side. It contains the descending part of the arch, the 
thoracic aorta, the azygos veins, and vagi, oesophagus, thoracic duct, 
and some lymphatic glands. 



THE LUNGS. 
Describe the lungs. 

The lungs are placed one in each side of the chest, in contact with its 
inner surface, and present each for examination an apex, a base, two 
1 (orders, and two surfaces. 

The apex extends 1 to H inches above the first rib. and is marked by 
a groove for the subclavian artery. The base is concave and rests on the 
diaphragm, its thin margin fitting into the space between the ribs and 
diaphragm. The outer surface is smooth and convex : the inner surface 
is concave and adapted to the pericardium, and behind is marked by a 
fissure, the hiluni pulmonis, for the root of the lung. The posterior 
border is rounded, fits into the concavity on either side of the spine, and 
is the longest part of the lung; the anterior border is sharp and over- 
laps the pericardium. That of the right lung runs mesially as far as the 



THE LUNGS. 317 

sixth cartilage ; the left only to the fourth cartilage, below which is a 
notch exposing the pericardium. 

What are the fissures of the lungs ? 

Each lung is divided by a deep fissure, which runs from the upper 
part of the posterior border. 3 inches below the top, to the lower part 
of the anterior border, into two lobes. The upper lobe of the right 
lung is subdivided by a short fissure running from the middle of the 
preceding fissure, forward and upward to the anterior margin, the pari 
below being the middle lobe. 

The right lung is the larger, although the shorter, and it is also the 
heavier. 

Describe the root of the lung. 

The root of each lung is a little above and behind the centre, and 
includes the bronchus, pulmonary and bronchial vessels, pulmonary 
plexus, areolar tissue, lymphatics, and bronchial glands, these all being 
enclosed by a fold^ of the pleura. The root of the right lung is placed 
behind the superior cava and ascending arch and below the azygos 
major vein, and the left under the arch of the aorta and in front of the 
descending part of the arch. In front of each are the phrenic nerve 
and anterior pulmonary plexus, and behind each are the posterior plexus 
and the vagus. 

The pulmonary vein, artery, and the bronchus and bronchial vessels 
lie in the order named from before backward ; from above downward on 
the right side they run, bronchus, artery, vein ; on the left side, artery, 
bronchus, vein. 

What are the weight and general structure of the lungs ? 

The right lung weighs 22 ounces, the left 20 ounces, and their color, 
at birth a pink, darkens with age. 

The lungs have an outer serous coat, under this a subserous coat, 
and under this latter the pulmonary parenchyma. The serous coat is 
the pleura ; the subserous areolar tissue under it enters in between the 
lobules. 

The lung is composed of lobules which are largest toward the periph- 
ery, and each is made up of a lobular bronchial tube with its ramifica- 
tions, and includes branches of the pulmonary and bronchial vessels, 
nerves, and lymphatics, all connected together by areolar fibrous tissue. 

What is the arrangement of the bronchi within the lung ? 

Both bronchi enter the lungs, the right giving off a branch to the 
upper lobe, dividing dichotomously, the cartilaginous rings becoming 
shorter until they are mere plates without regular distribution. The 
muscular coat is continuous around the tubes, and the mucous mem- 
brane throughout is columnar and ciliated. Each lobular bronchial tube, 
above mentioned, on entering a lobule becomes beset with air-cells or 



318 THE ORGANS OF DIGESTION. 

alveoli Finally, it ends as the alveolar passage, from which are given 
off blind ramifications or infundibula. These are also beset with air- 
cells. 

What can you say of the blood-vessels of the lungs ? 

The pulmonary artery divides, and its divisions accompany those of the 
bronchi. Finally a capillary plexus is formed on the walls of the air- 
cells and alveolar passages, which lies just beneath the mucous mem- 
brane, and from this plexus the pulmonary veins arise. 

The bronchial arteries nourish the lungs, and in like manner accom- 
pany the tubes. They supply also the bronchial glands, and end in the 
bronchial veins. These veins do not receive all the blood from the cor- 
responding artery, as the pulmonary veins return a part of it. The left 
empties into the superior intercostal ; the right, into the azygos major 
vein. 

THE ORGANS OF DIGESTION. 

THE MOUTH. 
Describe the mouth. 

The mouth is the upper part of the alimentary canal. It is bounded 
by the lips, cheeks, tongue, hard and soft palate, alveolar processes of 
both jaws, with their contained teeth, and opens behind, through the 
isthmus faucium, into the pharynx. It is lined by mucous membrane 
continuous in front with the skin, behind with that of the fauces, its epi- 
thelium being stratified. 

Describe the lips and cheeks. 

They are formed of skin externally and of mucous membrane inter- 
nally, enclosing between them muscles, vessels, nerves, areolar tissue, fat. 
and glands. In the cheeks are the buccal glands, similar to but smaller 
than the labial, and opposite the second upper molar tooth is a papilla, 
the summit of which presents the orifice of the parotid duct. Several 
larger buccal glands open opposite the last molar tooth. They lie be- 
tween the buccinator and masseter, and are called the molar glands. 
The labial glands are about the size of small peas, and lie just beneath 
the mucous membrane. The inner surface of each lip in the middle line 
is joined to the gum of the corresponding jaw by a mesial fold of mucous 
membrane, the framum. The upper is the larger. 

Describe the gums. 

They are formed of fibrous tissue intimately joined to the alveolar 
periosteum, and are covered by mucous membrane containing papillae 
close to the teeth. 

THE TEETH. 
Describe the teeth. 
There are in the human subject two sets of teeth, a temporary set, or 



THE TEETH. 319 

milk teeth, and a permanent set. The former are twenty in number, 
ten in each jaw ; the latter, thirty-two, sixteen each above and below. 
Each tooth is made up of three parts : the root, consisting of one or 
more fangs, contained in the alveolus ; the crown or body, above the gum ; 
and the neck, between the two. The alveolar periosteum is reflected 
on to the fang as far as the neck. 

How are the teeth divided? 

The twenty temporary teeth are divided into four incisors, two canines, 
and four molars above and below. The thirty-two permanent teeth are, 
four incisors, two canines, four bicuspids, and six molars in each jaw. 
The temporary teeth are similar to but smaller than the permanent; of 
the temporary molars, the hinder one is the largest of all, and its place 
is afterward taken by the second permanent bicuspid. 

Describe the permanent teeth. 

Of the permanent teeth the incisors are the eight central cutting- 
teeth, four each above and below, the former being the larger. They 
are bevelled at the expense of the posterior surface. The canines (cus- 
piclati) are two in each jaw, being situated one behind each lateral incisor, 
the upper and larger being called the eye-teeth. The bicuspids [pre- 
molars or false molars), four in each jaw, lie two each behind the canines, 
the upper being the larger. The molars (true molars or multicuspid at!) 
are the largest teeth, and number six in each jaw, three each behind the 
posterior bicuspids above and below. They present four tubercles on the 
upper, five on the low T er crowns, and the root is subdivided into from two 
to five fangs. The first molar is the largest and broadest, the second is 
smaller, and the third (wisdom tooth) the smallest. 

Give the structure of a tooth. 

A vertical section of a tooth shows it to be hollow, the cavity being- 
continuous with the aperture in the fang and filled up with the soft den- 
tal pulp, and is hence called the pulp-cavity. The pulp is sensitive, 
highly vascular, and consists of connective tissue with cells, vessels, and 
nerves. The hard substance of each tooth consists of three parts : the 
ivory or dentine, the enamel, and the crusta petrosa or cement. 

The dentine forms the chief mass, consisting of fine tubes, the den- 
tal tubuli, imbedded in a homogeneous matrix, the intertubular tissue. 
These tubuli open into the pulp-cavity. 

The enamel is a hard white substance which protects the crown of a 
tooth, being thickest at the cutting edge. It is the hardest part of the 
tooth, and consists of hexagonal rods, parallel and presenting one end to 
the dentine, the other to the crown. It also presents a series of brown 
lines, the parallel striae. 

The crusta petrosa covers the dentine of the root, which has no 
enamel. It resembles true bone of a somewhat modified structure, con- 
taining lacunae, lamellae, canaliculi, and some Haversian canals. 



320 THE ORGANS OF DIGESTION. 

Give the different periods of eruption of the different teeth. 

The period of eruption for the temporary teeth is from the seventh 
month to the end of the second year. They appear in the following 
order : central incisors, lateral incisors, anterior molars, canines, posterior 
molars. The lower precede the upper by a short period. The perma- 
nent teeth appear as follows : between the sixth and seventh year, first 
molars ; seventh year, middle incisors ; eighth year, lateral incisors ; 
ninth year, first bicuspids; tenth year, second bicuspids; eleventh to 
twelfth year, canine ; twelfth to thirteenth year, second molars ; seven- 
teenth to twenty-first year, wisdom teeth. 

THE PALATE. 
Describe the palate. 

The palate forms the roof of the mouth, and consists of a front part 
or hard, and a back part or soft palate. The periosteum of the hard 
palate (see Bones) is covered by and intimately connected with the 
mucous membrane of the mouth. In the middle line is a raphe ending 
in front at a small papilla, which marks the anterior palatine fossa which 
receives the terminal part of the anterior palatine and naso-palatine 
nerves. The mucous membrane is pale and corrugated, covered with 
squamous epithelioma, and furnished with a number of palatal glands 
which lie between it and the bone. 

Describe the soft palate (velum pendulum palati). 

It partially separates the mouth and pharynx. It consists of muscu- 
lar, connective, and adenoid tissue, with vessels, nerves, and mucous 
glands, all enclosed in a fold of mucous membrane. Above it is joined to 
the back of the hard palate ; laterally it blends with the pharynx ; below 
it is free ; in front it is concave, with a median ridge ; and behind it is 
convex. Its mucous membrane is continuous with that of the roof of 
the mouth and of the posterior nares. 

From its lower border a conical process depends, the uvula, from whose 
base descend the pillars of the soft palate, the anterior, formed by the 
palato-glossi muscles, to the sides of the base of the tongue; the pos- 
terior, formed by the palato-pharync/ei, to the sides of the pharynx. 
These pillars are covered by mucous membrane and separated below by 
the tonsil, tin 1 space being called the isthmus of the fauces. The mus- 
cles of the soft palate are five on each side, and lie in the following rela- 
tive position from before backward : the palato-glossus, tensor palati. 
anterior fasciculus of palato-pharyngeus, levator palati. azygos uvulae, 
and, lastly, the posterior fasciculus of the palato-pharyngeus. 

THE TONSILS. 
Describe the tonsils. 

The tonsils (amygdalae) lie between the anterior and posterior pala- 
tine pillars, and are about ? inch long and J inch wide and thick, but vary 



THE SALIVARY GLANDS. 321 

much in size. Externally they are separated by the superior constrictors 
from the internal carotid and ascending pharyngeal arteries ; internally 
they project into the fauces, and present twelve or more orifices which 
lead into the crypts in their substance. Around the crypt- walls are 
numerous lymphoid follicles consisting of adenoid tissue. 

THE SALIVARY GLANDS. 
Describe the salivary glands. 

There are three pairs, parotid, submaxillary, and sublingual. 

The parotid, the largest, weighs £ to 1 ounce, and lies on the face 
below and in front of the ear. Its outer surface, lobulated, is covered 
by the skin and fascia, and partly by the platysma and several lymphatic 
glands ; in front it runs over the masseter, is grooved for the ramus of 
the lower jaw, and extends beneath it, between the two pterygoids ; 
above it is bounded by the zygoma ; below by the angle of the jaw and 
a line joining it with the mastoid process ; behind by the external mea- 
tus, mastoid process, and sterno-mastoid. The internal surface sends 
two processes into the neck : one behind the styloid process and beneath 
the mastoid process and sterno-mastoid ; another in front of the styloid 
process, into the back of the glenoid cavity behind the jaw. Imbedded 
in the gland are found the external carotid, posterior auricular, tempo- 
ral, transverse facial, and internal maxillary arteries, the temporo-maxil- 
lary vein and a branch from it to the internal jugular, the facial nerve 
with its branches, and the auriculo- temporal and great auricular nerves. 
The internal carotid artery and internal jugular vein lie under its deep 
surface. 

The duct (Stenson's) is about 2 i inches long and £ inch in diameter, 
and opens opposite the second molar tooth, thence runs backward be- 
neath the mucous membrane, through the buccinator, and across the 
masseter to the front of the gland. It commences by numerous branches, 
and on the masseter receives the duct of a detached part of the gland, 
the soda parotidis, which sometimes is found beneath the zygomatic 
arch. Its epithelium is columnar. 

The submaxillary gland is of an irregular form, weighs about 2 
drachms, and lies below the jaw and above the digastric muscle. It is 
covered by the skin, platysma, and fasciae, and grooves the inner surface 
of tne lower jaw. It lies on the mylohyoid (partially embracing this 
muscle), hyoglossus, and styloglossus, and has in front of it the anterior 
belly of the digastric. Behind, the stylo-maxillary ligament separates it 
from the parotid, and the mylo-hyoid (its superficial part) from the sub- 
lingual gland in front. The facial artery grooves its upper and back part. 

The submaxillary duct (Wharton's) is 2 inches long, and opens at the 
top of a papilla close to the fraenum linguae. Thence it runs back be- 
tween the sublingual gland and the genio-hyoglossus, then between the 
mylo-hyoid and the hyoglossus and genio-hyoglossus. 

The sublingual gland, the smallest of the salivary glands, lies at the 
21— A. 



322 THE ORGANS OF DIGESTION. 

side of the fraenum linguae and against the inner surface of the lower 
jaw, beneath the mucous membrane. It is almond-shaped, weighs 1 
drachm, and its ducts {of Rivini ). ten to twenty in number, open sepa- 
rately, one or two joining to form the duct of Bartholin, which joins 
Wharton's duct. It is in relation below with the mylohyoid; in front 
with its fellow and the lower jaw ; behind with the submaxillary gland ; 
internally the gustatory nerve and Wharton's duct separate it from the 
genio-hyoglossus. 

THE PHARYNX. 

Describe the pharynx. 

The pharynx extends from the base of the skull to the lower border 
of the cricoid cartilage ; it is 4i inches long, wider transversely than 
antero-posteriorly, and widest opposite the hyoid cornua. Below it 
opens into the oesophagus ; above it is connected with six openings — 
viz. the mouth, larynx, the two posterior nares, and the two Eustachian 
tubes. 

The pharynx is formed of a fibrous coat, the pharyngeal aponeurosis, 
thick above, thinner below, lined by mucous membrane and covered by 
muscles. Above it is connected with the body of the sphenoid and the 
basilar process of the occipital bone ; behind with the spine, the longi colli 
and recti capitis antici muscles; in front with the internal pterygoid plate, 
pterygo-maxillary ligament, lower jaw, tongue, larynx, and os hyoides ; 
laterally are the styloid processes and their muscles, common and internal 
carotid arteries, internal pterygoid muscles, internal jugular veins, and 
the glosso-pharyngeal, vagus, hypoglossal, and sympathetic nerves. 
The pharyngeal aponeurosis is strengthened behind by a fibrous band 
which forms a median raphe, and is attached above to the pharyngeal 
spine on the basilar process of the occipital. Into it are inserted the 
constrictores pharyngis. A mass of lymphoid tissue at the back of the 
pharynx has been called the pharyngeal tonsil. 

THE CESOPHAGTJS. 
Describe the oesophagus. 

The oesophagus is the tube connecting the pharynx with the stomach, 
and extends from the level of the sixth cervical vertebra through the 
diaphragm, entering the stomach opposite the tenth or eleventh dorsal 
vertebra, a distance of 9 or 10 inches. At first in the median line, it 
runs to the left as far as the root of the neck, becomes again mesial, and 
lastly turns toward the left to pass through the oesophageal orifice in the 
diaphragm. It also corresponds to the cervical and dorsal curves of the 
spine. It is the narrowest part of the alimentary canal, and presents 
two constrictions, one at its commencement, the other at the diaphragm. 

In the neck it is in relation, in front, with the trachea ; behind, with 
the longus colli and spinal column ; lateral!}/, with the common carotid 



THE STOMACH. 323 

arteries and part of the thyroid gland. Between it and the trachea 
ascend the recurrent laryngeal nerves. 

In the chest it is in relation, in front, with the trachea, left carotid 
artery, left bronchus, and pericardium; behind, with the spine, longus 
colli, thoracic duct, and aorta; laterally, with the pleurae, and on the 
right side the large azygos vein, and on the left the aorta. The right 
vauus is behind, the left in front of, the oesophagus, but at first each is 
on the corresponding side. 

What is the structure of the oesophagus ? 

The oesophagus has an external muscular coat, which is composed of 
an external longitudinal and an internal circular layer, an areolar coat- 
between, and an internal mucous coat. This last is thick, paler below, 
and marked by longitudinal folds. Its surface presents numerous pa- 
pillae and is covered by stratified epithelium. Beneath it is a muscularis 
mucosae, and in the submucous or areolar coat are numerous compound 
racemose oesophageal glands. 

THE STOMACH. 

Describe the stomach — situation, measurements, orifices, and 
borders. 

The stomach lies in the epigastric and left hypochondriac regions, and 
is the most dilated part of the alimentary canal. Its shape is pyriform, 
the left or larger end being called the cardiac, the right the pyloric end. 
The left and right openings are termed respectively the cardiac or 
oesophageal orifice and the pyloric orifice. < In a state of moderate dis- 
tension it is 12 inches long and 4 inches in its vertical diameter, and 
weighs 4 to 5 ounces. 

The cardiac orifice is the highest part of the stomach, and lies behind 
the seventh costal cartilage, 1 inch to the left of the sternum ; the pyloric 
orifice is guarded by a valve, the pylorus. Between the two the stomach 
is curved, the upper concave border being known as the lesser, the lower 
convex border as the greater, curvature. The former gives attachment 
to the lesser, the latter to the great omentum. The left end (greater or 
splenic) extends 2 or 3 inches to the left of the cardiac orifice, forming 
the fundus or great cul-de-sac. The gastro-splenic omentum connects it 
to the spleen. The lesser or pyloric end lies inferior and anterior to the 
fundus, in contact with the liver and belly- wall, and its position varies 
according to the state of distension. 

Describe the relations of the stomach. 

Anterior Surface. 
Diaphragm. 

Under surface of left lobe of liver. 
Abdominal wall. 



324 THE ORGANS OF DIGESTION. 

Right End Left End. 

Abdominal wall. Lower ribs. 

Under surface of right lobe of liver. Spleen (and behind). 

Posterior Surface. 
Pancreas and pancreatic vessels. 
Abdominal aorta and inferior cava. 
Coeliac axis and branches. 
Crura of diaphragm and solar plexus. 
Superior mesenteric vessels. 
Left kidney and capsule. 
Spleen. 

[Below.) 
Transverse colon and transverse mesocolon, upper layer. 

Describe the structure of the stomach. 

The stomach has a serous peritoneal coat, a muscular coat comprising 
a longitudinal, circular, and oblique layer, an areolar coat ot loose 
tissue (submucous coat), and a mucous coat. The latter is thickest near 
the pylorus, thinnest at the fundus, and presents, in the empty condition 
of the organ, numerous ridges or rugae, which run longitudinally along 
the great curvature. Studded over its surface are many small polygonally- 
shaped depressions which are the enlarged mouths of the gastric tubular 
glands. These are of two kinds, called pyloric and peptic glands ; some 
are simply tubular, while others have several branches opening into a 
common duct. The pyloric glands are most numerous at the smaller 
end, but the peptic glands are found all over the stomach, the ducts of 
the latter being shorter. In the latter, between the basement membrane 
and the lining epithelium, are numerous peptic or parietal cells, the others 
being known as the central or chief cells. Between the glands the mucous 
membrane contains lymphoid tissue, collected here and there into little 
masses resembling the solitary intestinal glands, and called the lenticular 
glands. Beneath the membrane is a muscularis mucosae. 

THE SMALL INTESTINE. 

Describe the small intestine— situation, division, and attach- 
ments. 

The small intestine is about 20 feet long, and is a convoluted tube 
which forms that part of the alimentary canal between the pylorus and 
the caecum. It occupies the central and lower part of the abdomen and 
part of the pelvis, and is surrounded by the large gut. being held in 
position by the peritoneal fold called the mesentery, which is attached 
behind to the spine. It is covered in front by the great omentum, and 
is divided into three parts, the duodenum, jejunum, and ileum. 



THE SMALL INTESTINE. 325 

Describe the structure of the small intestine. 

The small intestine is made up of four coats : 

An external peritoneal coat, which completely invests the jejunum and 
ileum except at the mesenteric or attached border behind, where the 
vessels pass, and which only partially invests the duodenum. Of this 
latter, the first portion is completely invested, the second portion only in 
front, and the third is covered in front by peritoneum derived from the 
inferior layer of the transverse mesocolon. 

The muscular coat consists of an internal circular and an external lon- 
gitudinal layer. 

The areolar or submucous coat consists of loose connective tissue sup- 
porting the vessels. 

The mucous membrane is closely covered by villi, and is of a red color 
at the upper part, but thinner and paler below. Its epithelium is co- 
lumnar, and it is furnished with a muscidaris mucosae. The prominent 
features of the mucous membrane are (a) vedvuke conniventes (Kerk- 
ring's), crescentic transverse folds extending one-half or two-thirds 
around the circumference, the largest being 2£ inches long and £ inch 
wide. These folds are found from a point 1 to 2 inches from the pylorus 
to about midway through the ileum, {b) The villi, small projections set 
closely together over the entire mucous membrane surface of the small 
intestine, and about ^ inch long. Eacli villus consists of a projection of 
the mucous membrane enclosing blood-vessels, a lacteal, and a part of 
the muscularis mucosae, all held together by lymphoid tissue and sur- 
rounded by a delicate basement membrane beneath the epithelium, (c) 
Lieberkulin s follicles. These are small tubes found everywhere in the 
mucous membrane, and consist of a basement membrane lined by a layer 
of epithelium, (d) Brvnners glands are small granular bodies in the 
submucous tissue, their ducts opening on the mucous surface. They are 
found only in the duodenum and the commencement of the jejunum. 
(e) The solitary glands are small whitish bodies, most numerous in the 
lower part of the ileum. They are made up of very vascular retiform 
tissue, and on their surfaces are found villi and around them the openings 
of Lieberkuhn's glands. (/) Peyer s patches are oblong aggregations of 
solitary glands, measuring from | inch to 4 inches in length, and are 
situated on the border opposite to the attachment of the mesentery. 
Their surface is not covered by villi, and they are surrounded by Lieber- 
kuhn's crypts. They are most numerous in the lower part of the ileum. 



Give a general description of the duodenum. 

The duodenum is about 10 inches long (12 fingers), and runs in a 
curved direction from the pylorus to the jejunum, which it joins on the 
left side of the second lumbar vertebra. The concavity of the curve 
looks toward the left and embraces the head of the pancreas. It is 
divided, for description, into three parts. 



326 THE ORGANS OF DIGESTION. 

Name these three parts, and give the relations of each. 
First or Ascending Portion. 

Above and Front. 
Liver. 
Neck of gall-bladder. 

Behind. 
Hepatic artery. 
Com. bile-duct. 
Vena portse. 

Below. 
Part of head of pancreas. 

Second or Descending Portion. 
Front. 
Hepatic flexure of colon. 
Transverse mesocolon. 
Pancreatico-duod. arteries. 

Behind. 

Right kidney and suprarenal capsule (at times). 
Structures at hilus of kidney. 
Com. bile duct (and to left). 

Internally. 
Head of pancreas. 

Third or Transverse Portion. 

Above. 

Inf. border of pancreas. 
Sup. mesenteric vessels. 

Front 

Peritoneum derived from descending layer trans, mesocolon. 
Sup. mesenteric vessels. 

Behind. 
Aorta and inf. cava. 
Crura, diaphragm. 
Second lumbar vert. 

Describe the jejunum and ileum. 
The jejunum includes the first two-fifths of the remaining part of the 



THE LARGE INTESTINE. 327 

small intestine, running from the loft side of the second lumbar vertebra 
to the beginning of the ileum, and occupying the umbilical and left 
lumbar and iliac regions. Its coats are thicker and more vascular, and 
it is of a deeper color and larger calibre, than the ileum. 

The remainder of the small intestine is the ileum, which ends by open- 
ing into the inner side of the commencement of the large gut in the 
right iliac fossa. Its coils occupy the hypogastric, umbilical, and right 
lumbar and iliac regions. 



THE LARGE INTESTINE. 

Describe the large intestine. 

The large intestine is that part of the alimentary canal which extends 
from the end of the ileum to the anus ; it is about 5£ feet long, and sur- 
rounds the small intestine. It commences by a dilated part, the ccecum, 
in the right iliac fossa, ascends to the under surface of the liver, then runs 
transversely across the abdomen to the vicinity of the spleen, descends 
to the left iliac fossa, and forms the sigmoid flexure, and finally passes 
along back of the pelvis to end at the anus. 

What is the caecum? 

The caecumis the large cul-de-sac which is the beginning of the large 
intestine, and is about 3 inches broad and 2 1 long. It is variously situated, 
being found on the psoas, external to it, on the iliacus, internal to it, on 
the pelvic brim, or entirely within the pelvis. In any of these positions 
it is entirely surrounded by peritoneum. 

Describe the vermiform appendix. 

From the inner and back part of the caecum, at its lower end, the ver- 
miform appendix extends upward and inward behind it. This is a piece 
of gut of the diameter of a goose-quill, varying from 3 to 6 inches in 
length, curved upon itself, and ending in a blind extremity. It tapers 
gradually to its end, which is blunt, is completely invested by the peri- 
toneum, which forms for it a mesentery, and at its connection with the 
caecum is guarded by an imperfect valve. 

Describe the ilio-caecal valve. 

The small intestine opens into the large gut about 2\ inches above the 
lower extremity of the caecum in an oblique direction. Its opening is 
guarded by a double fold forming the iho-ccecal valve, which lies trans- 
versely to the long axis of the colon. Each fold of the valve is made 
up of the mucous and submucous coats, reinforced by some circular fibres 
from the muscular coat, of each portion of the gut. and is covered on 
the side toward the ileum with villi. At each end of the opening these 
folds run together and are prolonged some distance around the gut, form- 
ing the retinacula. 



328 THE ORGANS OF DIGESTION. 

Describe the ascending colon. 

This part of the large gut runs from the caecum, above the ileo- 
cecal valve, upward to the under surface of the liver on the right side 
of the gall-bladder, and then turns forward and to the left to form the 
hepatic flexure The peritoneum rarely forms lor it a mesocolon ; gene- 
rally it covers only the front part and the sides. It occupies the right 
lumbar and hypochondriac regions. 

Describe the transverse colon. 

This part arches across the abdomen, the convexity looking toward the 
belly-wall, and makes a sudden turn backward and downward beneath the 
spleen, forming the splenic flexure, and is completely invested by the peri- 
toneum. It occupies the right hypochondriac, upper part of umbilical 
and left hypochondriac regions. At the splenic flexure is attached the 
costo-colic ligament, a fold of peritoneum extending to the diaphragm 
opposite the tenth or eleventh rib. 

Describe the descending colon. 

This part descends from the splenic flexure, to end at the left iliac 
fossa in the sigmoid flexure. It is covered in front and laterally by the 
peritoneum. It occupies the left hypochondriac and lumbar regions. 

Give the relations of each of the three portions of the colon. 

First or Ascending Portion. 

Front. 
Ileum. 

Abdom. wall. 
Great omentum. 

Behind. 
Quadratus lumborum. 
Right kidney (lower part). 
Second portion duod. (hepatic flexure). 

Second or Transverse Portion. 
Above. 
Liver and gall-bladder. 
Stomach (gt. curvature). 
Splenic f Spleen (lower end), 
flexure, j Pancreas (tail). 

Below. 
Small intestines. 



THE RECTUM. 329 

Behind. 
Transverse mesocolon. 

Third or Descending Portion. 

Front. 
Jejunum. 
Abdom. wall. 

Behind. 
Left kidney (along left border of lower part ant. surface). 
Quadrat us lumborum. 

Describe the sigmoid flexure. 

The sigmoid flexure ends in the rectum. From the end of the de- 
scending colon it forms an S-shaped curve, ending opposite the left sacro- 
iliac joint. In front of it are the belly- wall and some coils of small in- 
testine. The peritoneum forms a loose mesocolon for it, It is the 
narrowest part of the colon. 

Describe the rectum. 

The rectum is the lowest part of the large intestine, and extends from 
the sigmoid flexure to the anus. It has been divided into three parts : 
the first part extends from the left sacro-iliac joint to the centre of the 
third piece of the sacrum ; the second part, to the tip of the coccyx ; 
and the third part, to the anus. 

The rectum is about 8 inches long and somewhat cylindrical in form, 
narrower above than the sigmoid flexure, but it enlarges as it descends, 
and just above the anus is remarkably dilated, forming the ampulla. 
The first part has a mesorectum ; the second part is covered by perito- 
neum in front and laterally ; the third part has no peritoneal covering. 

Give the relations of the first and second part of the rectum. 

The first part of the rectum is about one-half of its whole length, 
and has the following relations: 

Behind. 

Pyriformis. 

InTilia P o e it^ and branches, } ° f *» ^ *"> <***■ 

Front. 

Male. Female. 

Post, surface of bladder. Post, surface of uterus and 

appendages. 
(Small intestines intervening in both cases.) 



330 



THE ORGANS OF DIGESTION. 



The second part is about 3 inches long, and has the following re- 
lations : 

Behind. 

Concavity of sacrum. 
Middle sacral artery. 



Front. 
Male. 

Triangular part of bladder. 
Vesiculae seniinales. 
Vas deferens. 
Under surface of prostate. 



Female. 
Post, vaginal wall. 
Cervix uteri. 



Describe the third or lower part of the rectum, and give its 
relations. 

The third part is 1 to 1J inches long, and curves backward and down- 
ward to end at the anus, where it is surrounded by the external sphinc- 
ter. Higher up the internal sphincter surrounds it, and the levatores 
ani support it on each side. In front of it are the membranous and 
bulbous portions of the urethra, but separated from it by a triangular 
cellular space whose base is the central point of the perineum. In the 
female, in front, vagina and perineal body. 

Describe the structure of the large intestine. 

It has four coats — serous, muscular, submucous, and mucous. 

The serous coat is peritoneum, and along the anterior margin of the 
gut it presents numerous little projections called appendices epiploicse, 
which are filled with fat. 

The muscular coat is divided into two layers, longitudinal and circular, 
the former being external. The circular layer is disposed generally over 
the surface. 

The longitudinal layer is seen as three well-marked bands h inch wide 
and h line thick. These bands commence on the caecum at the origin 
of the vermiform appendix, and have the following arrangement on the 
three divisions of the colon respectively: the anterior band runs along 
the anterior border of the ascending, the transverse, and descending 
colon: this band serves for the attachment of the great omentum to 
the transverse colon ; the posterior band extends along the posterior 
border of the entire colon, and indicates the line along which the perito- 
neum leaves the ascending and descending colon, and along the trans- 
verse colon it is the line of coalescence of the two layers of the trans- 
verse mesocolon ; the inner band is on the inner border of the ascending 
and descending colon and on the under border of the transverse colon. 
It is along this band that the appendices epiploicae are found. 

The submucous coat is made up of areolar tissue. 



THE LIVER. 331 

The mucous coat or mucous membrane is smooth, lias no villi, con- 
tains crypts of Lieberkiihm, and has lymphoid nodules scattered over its 
surface. 

What can you say of the structure of the rectum ? 

The longitudinal fibres of its muscular coat are disposed in a uniform 
layer. There are no bands. The mucous membrane has numerous folds, 
which near the anus are longitudinal in direction and are known as the 
columns of Morgagni. At and above the level of the prostate gland 
there are three other prominent folds, having more or less a horizontal 
direction. These are called the folds of Houston. 

THE LIVER. 
Give the general position and measurements of the liver. 

The liver lies in the epigastric and right hypochondriac region, reach- 
ing partly into the left hypochondrium, weighs between 3 and 4 pounds, 
and measures 10 to 12 inches transversely, 6 to 7 inches from before 
backward, and 3£ inches vertically at its thickest part. 

Give the relations of the liver. 

Above. 
Diaphragm. 
Abdom. wall. 

Below. 

Stomach, duodenum (first part). 
Hepatic flex, colon. 
Right kidney and suprarenal capsule. 
Grail- bladder and duct (cystic). 

Behind. 

Diaphragm. 

Aorta and inf. cava. 

How is the liver divided ? 

The upper surface is divided by the suspensory ligament, and the lower 
by the longitudinal fissure, into a right and a left lobe. The anterior 
thin border is notched opposite the suspensory ligament. The right ex- 
tremity is thick, the left thin and flattened. 

Name and describe the ligaments of the liver. 

They are all peritoneal folds excepting the round ligament, which is a 
fcetal'remnant. The longitudinal (suspensory or broad) ligament is broad 
and thin, runs from before backward, and is attached above to the dia- 
phragm and sheath of the right rectus muscle as far as the umbilicus ; 
below to the superior surface of the liver, from the posterior border to 
the notch in the anterior border. The free anterior border has between 



.332 THE ORGANS OF DIGESTION. 

its layers the round ligament, which is the shrivelled and impervious 
remains of the foetal umbilical vein. It runs along the longitudinal fis- 
sure from the umbilicus to the vena cava. The lateral ligaments are 
peritoneal folds which extend between the diaphragm and the corre- 
sponding borders of the liver, the left being to the left of the oesoph- 
ageal opening. The coronary ligament is a process of peritoneum which 
is reflected on to the posterior surface of the liver in the situation of its 
apposition with the diaphragm. It is continuous with the lateral liga- 
ments on each side and with the suspensory in front. 

Name and describe the fissures of the liver. 

They are five. The longitudinal separates the right and left lobes. 
It is joined by the transverse fissure, the part in front of that point being 
called the umbilical fissure, and lodging the umbilical vein or its remains, 
the round ligament. The fissure of the ductus venosus is the part of the 
longitudinal fissure behind the transverse. It lodges the ductus veno- 
sus or its remains. The transverse or portal fissure is the point of exit 
and entrance of the vessels, nerves, and ducts. It lies between the quad- 
rate and Spigelian lobes. The fissure for the gall-bladder is parallel to 
the longitudinal on the under surface of the right lobe. The fissure for 
the inferior vena cava, sometimes a complete canal, lies to the right of 
the Spigelian lobule. 

Name and describe the lobes of the liver. 

These are also five in number. The right is the largest, being six times 
as large as the left, and is separated from the left above and below by the 
suspensory ligament and longitudinal fissure respectively, and in front by 
the interlobar notch. Its under surface is marked by the transverse fissure 
and that of the gall-bladder, and its posterior surface by that of the infe- 
rior vena cava, and anteriorly is the impressio colica for the hepatic flexure, 
and behind another, the impressio renalis, for the right kidney. The left 
lobe is flattened, lies in the epigastrium, and is in relation below with the 
stomach. The lobus quadrafus is on the under surface of the right lobe, 
and is bounded in front by the free surface of the liver, behind by the 
transverse fissure, on the right by the fissure for the gall-bladder, on the 
left by the umbilical fissure. The Spigelian lobe lies behind and above 
the preceding, and is bounded in front by the transverse fissure, on the 
right by the fissure of the vena cava, and on the left by the fissure for 
the ductus venosus. The caudate lobe runs outward from the base of the 
Spigelian lobe to the under surface of the right lobe, lying between the 
transverse fissure and that for the inferior vena cava. 

Describe the vessels of the liver. 

The hepatic artery and portal vein, with nerves and lymphatics, pass 
to, and the hepatic ducts pass out from, the transverse fissure. These 
are all situated between the layers of the lesser omentum, lying in the 



THE GALL-BLADDER. 333 

following relative position : the duct to the right, the artery to the left, 
and the vein between them and cm a posterior plane. The}' are all 
enclosed in some loose areolar tissue. Glisson's capsule, and a prolonga- 
tion of this tissue accompanies them through the liver. 

The hepatic veins, three large and several small, empty into the infe- 
rior vena cava. The nerves come from the coeliac plexus, right phrenic, 
and both vagi. 

THE GALL-BLADDER. 
Describe the gall-bladder. 

This is a pear-shaped sac lying in the impression of the right lobe, 
from the right end of the transverse fissure to the anterior free margin. 
It is 4 inches long and 1$ inches broad, holding 8 to 12 drachms, and 
is held in place by areolar tissue and the peritoneum. The fundus looks 
downward, forward, and to the right ; the body and neck upward, back- 
ward, and to the left. 

What are the relations of the gall-bladder ? 

Body. 

Above. 
Liver. 

Below. 
Ascending duod. 
Pyloric end of stomach. . 
Hepatic flexure of colon. 

Fundus. 
Front. 
Abdominal wall (ninth or tenth costal cart.). 

Behind. 
Transverse colon. 

Describe the biliary ducts. 

The hepatic duct is formed by the junction at an obtuse angle of a 
branch from each lobe, and runs downward and to the right for nearly 

2 inches, and joins the cystic duct to form the common bile-duct. The 
cystic duct is 1? inches long, and descends toward the left and joins the 
above as described. The common bile-duct is nearly 3 inches long and 

3 lines in diameter. It runs along the right border of the lesser omen- 
tum behind the first part of the duodenum, then between the pancreas 
and descending duodenum, then to the right of the pancreatic duct, witfc 
which it opens by a common orifice at the summit of a papilla just below 
the middle of the inner wall of the second portion of the duodenum. 



334 THE ORGANS OF DIGESTION. 

THE PANCREAS. 
Describe the pancreas. 

This is a long- gland, flattened from before backward, tapering to its 
left end, the tail, and enlarged at its right end, the head, between these 
two points being the body. It lies in the back part of the epigastric 
and left hypochondriac regions, being about 6 to 8 inches long, and less 
than 1 inch thick, and 1§ inches broad. Its weight is variously stated at 
2 to 6 ounces. 

The head is curved upon itself, and often gives off a projection of its 
substance behind, which, with the remainder of the organ, encloses the 
superior mesenteric vessels. This portion is sometimes detached, and is 
called the lesser pancreas. The pancreas has two broad surfaces, ante- 
rior and posterior, and a narrow inferior surface. 

Give the relations of the pancreas. 

Above. 
Cceliac axis. 

Splenic vessels (vein behind). 
Hepatic artery. 

Front. 

Post, surface of stomach. 

Peritoneum derived from superior layer trans, mesocolon. 

Right Side. Left Side. 

Ascending duod. [above). Spleen. 

Com. bile-duct [behind). 
Pancreatico-duod. artery {in front). 
Descend duod. ) r . „ ■ ai . 
Right kidney. } ^buts against. 

Right suprarenal capsule (behind). 
Trans, duod. [below). 



Behind. 
First lumbar vert. 
Crura of diaphragm. 
Sup. mesenteric vessels. 
Int. mesenteric vein. 
Splenic vein. 

Left kidney and suprarenal capsule. 
Left renal vessels. 
Thoracic duct. 
Vena portae. 
Aorta and inf. cava. 



THE SPLEEN AND SUPRARENAL CAPSULES. 335 

Below. 
Sup. mesenteric vessels. 
Inf. mesenteric vein. 
Splenic flex, colon. 
Transverse duod. 
Peritoneum derived from inferior layer trans, mesocolon. 

The duct of the pancreas runs from left to right and empties into the 
duodenum as described. It is called the duct of Wirsung. 

THE SPLEEN AND SUPRARENAL CAPSULES. 

THE SPLEEN. 
Describe the spleen. 

The spleen is placed at the back of the left hypochondrium, and in the 
axillary line extends from the eighth to the eleventh rib. It is oval in 
shape, highly vascular, of a pulpy consistency, very brittle, and is of a 
peculiar purplish color. The anterior surface is marked by a vertical 
depression, the hilus, which affords entrance and exitto the vessels. 
Here the peritoneum, which invests the spleen, passes in a double fold 
to the stomach as the gastro-splenic omentum. 

The organ consists of a fibrous trabecular framework containing and 
supporting the red splenic pulp and the vessels. Within the pulp, 
scattered here and there, are lighter-colored bodies, the Malpighian cor- 
puscles. These are developed on one side of the arterial branches or 
entirely surround these vessels, and are composed of lymphoid tissue. 

"What are the relations of the spleen ? 

Externally and Posteriorly. 
Ninth, tenth, and eleventh ribs. 
Costo-phrenic sinus and diaphragm. 

Above. Below. 

Diaphragm. Splenic flexure of the colon. 

Costo-colic lig. 

Internally. 
Ant Part. Post. Part. 

Great end of stomach, Left kidney and suprarenal capsule. 

Tail of pancreas. 

THE SUPRARENAL CAPSULES. 

Describe the suprarenal capsules. 

These are two flattened bodies, in shape resembling a cocked hat, 
which lie upon the upper border of the kidneys, to which they are united 



336 



THE URINARY,. ORGANS AND PERITONEUM. 



by loose areolar tissue. Ther are concave below, convex above, and 
marked in front by the hilus, from which emerges the suprarenal vein. 
Each measures vertically about H inches, transversely 1} inches, and is 
about £ inch thick. They weigh each about 2 drachms. 

Give the relations of the suprarenal capsules. 

Posteriorly. 
Diaphragm at junction of lumbar and costal parts, at level of eleventh 
or twelfth dorsal vertebra. 

Anteriorly. 



Right Capsule. 
Post, surface of liver. 

Peritoneum from liver to ant, sur- 
face of right kidney. 



Left Capsule. 
Spleen at upper and outer end. 
Pancreas. 

Peritoneum of lesser sac separating 
it from cul-de-sac of stomach. 



Vena cava (sometimes). 



Internally. 

Suprarenal arteries and veins. 



THE URINARY ORGANS AND PERITONEUM. 

THE KIDNEYS. 
Give the general shape, position, and measurements of the kidneys. 

The kidneys lie one on each side of the vertebral column, behind the 
peritoneum, opposite the last dorsal and upper two or three lumbar 
vertebrae. Each is bean-shaped, measures about 4 inches in length, 21 
in breadth, and 1 to 1 £ inches in thickness, and weighs about 4i ounces. 
The right is somewhat lower than the left, as well as somewhat shorter 
and broader. 

The anterior surface of the kidney is convex and looks somewhat out- 
ward. 



Give the relations of the kidneys. 

Front. 
{Right kidney.) 
Post, part of under surface r. lobe 

of liver. 
Descend, duod. (along left border). 
Hepatic flexure colon (below). 

Behind. 
Cms diaphragm. 
Quadratus lumborum. 

Psoas (and internally) 



{Left kidney.) 

Great end of stomach. 

Pancreas in the middle. 

Splenic flexure of colon 

(at some distance). 



THE URETERS. 337 

Externally. Internally. 

Abdoin. wall. Vessels at hilus and ureter. 

Spleen (left kidney). Psoas magnus. 

Descend, colon (left kidney). [The ureter lies behind and below 

the vein and artery. The vein is 
in front of the artery.] 

Above. 

Suprarenal capsule (somewhat anteriorly and internally). 

Describe the structure of the kidney. 

The kidney has a distinct capsule, beneath which is some unstriped 
muscle, and contains within it a central cavity or sinus. The duct or 
ureter commences by a dilated part, the pelcis, which is itself made up 
of smaller tubules, the calyces. The kidney substance is made up of a 
cortical part and a medullary part. The latter is composed of pyramidal 
masses of a darker-colored tissue, their bases looking toward the periph- 
ery. They contain uriniferous tubules which at the apices of the pyra- 
mids open into the calyces, which, in turn, make up the pelvis. 

(For a more detailed description of the structure of the kidney, see 
Histology of this series. ) 

THE URETERS. 
Describe the ureters. 

These tubes convey the urine from the kidneys to the bladder. Each 
is 16 to 18 inches long, of the diameter of a goose-quill, and runs down- 
ward, forward, and inward. 

What are its relations ? 

Front. 
Peritoneum. 
Spermatic vessels. 

(Left ureter) sup. hemorrhoidal artery. 
Ileum (right ureter). 
Sigmoid flex, (left ureter). 
Bladder. 

The pelvis of the ureter is on a level posteriorly with the spinous pro- 
cess of the first lumbar vertebra. 

Behind. Internally. 

Psoas. Inf. cava (right ureter). 

Com. iliac artery at its bifurcation. Vas deferens. 

Ureter enters post, false vesical ligament, with vas deferens between it 
and the bladder. 
22— A. 



338 THE URINARY ORGANS AND PERITONEUM. 

THE BLADDER. 
Describe the bladder. 

The bladder lies in the pelvic cavity behind the pubes, in front of the 
rectum (vagina and uterus coming between in the female). It is a mus- 
culo-membranous bag, and measures, when moderately distended, 5 inches 
in length and 3 in width, and holds about a pint, 

How is the bladder divided? 

It is divided into a summit, superior surface, base, inferior surface, 
and sides. 

The summit, looking forward, is connected to the umbilicus by the 
urachus centrally and the obliterated hypogastric arteries laterally. 

The superior surface extends from the summit to just above the bot- 
tom of the recto-vesical pouch. It is entirely covered by peritoneum. 

The base extends from the superior surface to the prostate gland. It 
is triangular in shape, with the apex at the prostate, and is bounded 
laterally by the vasa deferentia and vesicuke seminales. It has perito- 
neal covering only for a small distance just above the recto-vesical pouch. 

The inferior (or pubic) surface extends from the prostate gland to the 
summit, and rests on the triangular ligament, posterior surface of body 
of pubes. and lower part of anterior abdominal wall. 

The sides are in apposition with the recto-vesical fascia and obturator 
internus muscle. 

When empty the bladder collapses into the pelvis, and'in section pre- 
sents a triangular outline with the apex toward the symphysis. 

What are the relations of the bladder ? 

Above. 
Abdom. wall. 
Small intestines. 

Front. Behind. 

Triangular lig. Peritoneum. 

Symp. pubis. Rectum. 

Abdom. wall. Uterus (female). 

Pre-vesical space of Retzius (when distended). Small intestines. 
Prostatic plexus. 

Sides. 

Hypogastric artery. 

Ureter, obturator internus. 

Vas deferens, recto-vesical fascia. 

Base. 

Rectum (cervix uteri female). 
Vesiculpe seminales (vagina female). 
Vas deferens, 
Prostate, 



THE PERITONEUM. 339 

Name the ligaments of the bladder. 

They are divided into true ligaments, or those formed by the recto- 
vesical fascia, and in addition the urachus ; and the false ones, or those 
formed of peritoneum. 

The true ligaments include the two anterior or pubo-prostatic and the 
two lateral. The former run between the bladder and prostate; the 
latter between the bladder and sides of the pelvis. 

The false ligaments are a superior, from summit of bladder to navel, 
two lateral, to the iliac fossae, and two posterior. These latter run be- 
tween the rectum and bladder (uterus and bladder in the female). They 
contain the ureters. The hypogastric arteries lie between each lateral 
ligament and the corresponding posterior ligament. The bladder has a 
serous or peritoneal coat, a muscular coat of three layers, a submucous 
areolar coat, and a mucous coat, 

Describe the interior of the bladder. 

The mucous membrane is loosely attached except over the trigone. 
This is a triangular area whose apex corresponds to the urethral opening, 
and whose base extends between the orifices of the ureters, indicated by 
a curved elevation due to a muscular band. Extending from the open- 
ing of the urethra is another elevation due to submucous thickening, the 
uvula vesica'. In the female this is indistinct and the trigone is small. 

THE PERITONEUM. 
What is the peritoneum? 

The peritoneum is a closed serous sac which invests more or less com- 
pletely the contents of the abdominal and pelvic cavities, sending in 
processes or diverticula between the adjacent viscera. These processes 
are attached to the surfaces of the viscera, forming their investment, 
and serving also to separate and allow a free movement between them 
without friction. Moreover, they confine the viscera in their proper rela- 
tive positions. 

The walls of the peritoneum are very thin, the attached surfaces being 
rough ; the free, smooth and moist and covered with a layer of endothe- 
lium. That part which is attached to the inner surface of the abdominal 
walls is called the parietal layer, while that investing the viscera consti- 
tutes the visceral layer. 

Describe the general arrangement of the peritoneum. 

Starting from the anterior abdominal wall, the peritoneum passes 
around on the right side to completely invest the lower part of tbe caecum 
and the vermiform appendix, but only partially (?) investing the rest of 
the caecum, covering its front and sides, the back part being veryoften 
uncovered. It partially invests the entire ascending colon in a similar 
manner. Quite often, however, the back part of the caecum is also 



340 THE URINARY ORGANS AND PERITONEUM. 

covered by the peritoneum, which thus forms ;i mesocsecuin. It now 
covers the lower part of the front of the right kidney and the front of 
the third portion of the duodenum, passes thence to the spine, and, 
forming the right side of the mesentery, invests the jejunum and ileum, 
and returns, as the left layer of the mesentery, to the spine, thus com- 
pleting the structure. The peritoneum now crosses the lower part of 
the Lett kidney, invests the descending colon in a manner similar to that 
on the right side, forms a long sigmoid mesocolon, and returns to the 
front of the abdomen. 

Starting from the same place, we may trace the peritoneum downward 
to completely invest the rectum in its upper part and partially invest it 
below, at first covering it in front, and laterally lower down, only in 
front, and lastly leaving the gut altogether. It is then reflected on to 
the base and upper part of the bladder in the male, forming the recto- 
vesical pouch. This pouch presents on each side a fold, the plica semi- 
lunaris. From the apex of the bladder it ascends, investing the urachus 
and obliterated hypogastric artery on each side. In the female it passes 
from the rectum to the upper part of the vagina, forming the pouch of 
Douglas, which presents plicae semilunares similar to those found in the 
recto-vesical pouch in the male. It then covers both surfaces of the 
uterus, and forms the broad ligaments, investing the Fallopian tubes to 
the fimbriated ends, where it becomes continuous with their mucous mem- 
brane. 

Above, the peritoneum runs on the under surface of the diaphragm as 
far back as the oesophageal opening, and meets the process of the lesser 
sac, which lies on the posterior surface of the liver. It also forms the 
coronary, lateral, and falciform ligaments. At the anterior border of 
the liver it is reflected on to the under surface, covers the quadratic 
lobe, and at the transverse fissure it meets the posterior layer of the 
lesser or gastro-hepatic omentum from the lesser sac, and passes with it 
to the lesser curvature of the stomach as the anterior layer, thus com- 
pleting the omentum. From the quadrate lobe it invests the gall-blad- 
der to a variable degree, the under surface of the right lobe of the liver, 
the front of the second portion of the duodenum, and the upper part of 
the right kidney, forming here the fold known as the hepato-renal liga- 
ment. Lastly, it invests the hepatic flexure of the colon, and proceeds 
to the right colon in the manner previously described. 

To the left of the longitudinal fissure of the liver it covers the entire 
under and upper surface of the left lobe of the liver, forming the left 
lateral ligament. Tracing to the left the anterior layer of the lesser 
omentum, the peritoneum covers the front and left side of the oesophagus 
and left end of the stomach, passing thence to invest the spleen, and 
forming the anterior layer of the gastro-splenic omentum. Passing from 
the diaphragm to the stomach to the left of the gullet, there is formed the 
gastro- phrenic fold or ligament, and between the diaphragm and splenic 
flexure the costo-colic ligament. 



THE PERITONEUM. 341 

Describe the lesser sac of the peritoneum. 

This is a process of the peritoneum which lines the space bounded by 
the posterior surfaces of the liver and stomach and the upper surface of 
the transverse colon. It communicates with the greater sac by means of 
the foramen of Winslow, which is bounded in front by the lesser omen- 
tum, with the portal vein and hepatic artery and duct between its layers, 
behind by the vena cava inferior, above by the lobus caudatus, below by 
the duodenum. From this point the lesser sac lines the posterior abdom- 
inal wall, and adheres to the back of the greater sac except where the 
stomach comes between. Above it passes behind the liver, between the 
Spigelian lobule and the back part of the diaphragm, to meet the pro- 
cess from the greater sac already described. Here it is attached to the 
transverse fissure and the fissure of the ductus venosus, covering the 
oesophagus behind and on the right. At the transverse fissure it passes 
to the lesser curvature of the stomach, forming the posterior layer of the 
lesser or gastro-hepatic omentum, the anterior layer coming from the 
greater sac. It then invests the back of the stomach, ana! descends 
from the great curvature in front of the transverse colon and small intes- 
tine to a greater or less extent, Turning upon itself, it ascends, thus 
forming the internal layers of the great omentum, as far as the trans- 
verse colon, whose upper surface it invests, and passes thence to the 
spine, thus forming the upper layer of the transverse mesocolon. It 
now passes upward over the front of the pancreas, cceliac axis and its 
branches, upper part of left kidney, the left suprarenal capsule, and that 
part of the diaphragm between the aortic and caval openings, and is 
continuous with that part of the lesser sac lining the space back of the 
liver, already described. Traced to the left over the pancreas, the peri- 
toneum is reflected to the hilus of the spleen, and thence to the stomach, 
forming the posterior layer of the gastro-splenic omentum. Traced to 
the right, it is reflected from the extreme end of the pancreas on to the 
back of the first portion of the duodenum, and becomes continuous with 
that covering the posterior surface of the stomach. 

Describe the formation of the great omentum. 

The anterior layer of the lesser omentum invests the front of the 
stomach to the greater curvature, from which it descends in front of and 
with the posterior layer, and thus in front of the transverse colon and 
small intestine, to a variable degree. Still outside of the posterior layer 
(from the lesser sac), it is reflected, in a manner similar to that layer, 
upon itself, and, ascending with it, completes the great omentum. Those 
layers, therefore, of the great omentum which are contributed by the 
lesser sac are continued within those from the greater sac. At the trans- 
verse colon the layers of the greater omentum separate and enclose the 
gut, meeting behind and completing the transverse mesocolon, which 
extends to the lower border of the pancreas. Here the inferior layer 
(from the greater sac) runs down along the posterior abdominal wall and 



342 ORGANS OF REPRODUCTION (MALE). 

blends with the mesentery as described, and the superior layer (from the 
lesser sac) proceeds as already mentioned. 

ORGANS OF REPRODUCTION (MALE). 

THE PROSTATE GLAND. 

The prostate gland surrounds the so-called neck of the bladder and 
the commencement of the urethra. It rests against the rectum behind, 
and lies on the subpubic fascia (posterior layer of triangular ligament). 
It resembles a chestnut in form, and measures transversely lo- inches, from 
base to apex 1 } inches, and nearly 1 inch in thickness, its weight being 6 
drachms. The base looks toward the ueck of the bladder, its apex touches 
the deep perineal fascia (triangular ligament), the jjosterior surface is 
joined to the rectum by areolar tissue, and its pubic surface, grooved 
longitudinally, lies f inch from the pubic symphysis. It is supported in 
its position by the pubo-prostatic ligaments, posterior layer of the deep 
perineal fascia, and the front of each levator ani (the levator prostatas). 

The prostate consists of two lateral lobes and a middle lobe. The 
lateral hbes are separated behind by a deep notch, and are continuous in 
front of the urethra. The middle is smaller, lying between the lateral 
lobes, the bladder, and the adjacent portion of the urethra. 

The urethra and common seminal ducts pierce the prostate. The gland 
lias a dense, firm, fibrous capsule, which is derived from the recto-vesical 
fascia and the posterior layer of the triangular ligament, and it consists 
of glandular and muscular tissue. 

THE PENIS. 
Describe the penis. 

The penis consists of three cylindrical masses of erectile tissue united 
together, the two upper of which, lying side by side and called the 
corpora cavernosa, form the chief bulk of the organ, and the lower, the 
corpus spongiosum, contains part of the urethra. The root is attached 
to the pubic rami by the crura, and to the symphysis by the suspensory 
ligament. The body is cylindrical when flaccid, triangular with rounded 
border and sides when erect, the upper side being the dorsum. It is 
covered by a very thin skin, which is dark in color and devoid of adipose 
tissue, being loosely connected to the organ. This skin folds upon itself 
in front to form the prepuce, the under layer of which joins the cervix 
and becomes very like a mucous membrane, covering the glans and blend- 
ing into the mucous membrane of the urethra at the meatus. Around 
the cervix and corona glandis are small glands, the glandulae Tysoni 
odoriferne. The glans is conical and points anteriorly, its summit pre- 
senting a vertical slit, the meatus urinarins, from the lower part of 
which a fold of mucous membrane runs back to join the prepuce, and 
is called the Jrcenum praputii. The base of the glans projects at its 



THE MALE URETHRA. 343 

circumference, forming the corona gland is, behind which is a constriction, 
the cervix. 

The corpora cavernosa are closely connected for the anterior three- 
fourths, being flattened mesially, while behind they separate, and, 
enlarging at first to form the bulb of the corpus cavernosuin. gradually 
taper, and under the name of crura penis are attached to the rami of 
the pubes and ischium. In front they form a single blunt extremity 
which is joined by fibrous tissue to the base of the glans. Below them 
is a groove for the corpus spongiosum, and above one for the dorsal vein 
of the penis. 

The fibrous envelope is composed of longitudinal fibres common to 
both corpora, and circular fibres which are internal and belong to one 
corpus only. Mesially, where the circular fibres of both sides meet, they 
unite to form a septum. This septum is thick and complete behind, but 
in front many vertical slits allow of communication between the two 
bodies, and have given to the septum the name septum pectiniforme. 
From the inner surface of this envelope numerous fibrous trabecule 
pass in all directions. These trabecule support and enclose the arterial 
branches, which form a capillary network opening directly into the cav- 
ernous spaces, some of them forming convoluted vessels, the helicine 
arteries, which project into the trabecular spaces. The blood is returned 
by the dorsal vein, prostatic plexus, and pudendal veins. 

The corpus spongiosum commences behind, between the two crura, 
and in front of the deep perineal fascia, as the bulb, and in front ex- 
pands to form the glans. The bulb receives an investment from the 
anterior layer of the deep perineal fascia and is surrounded by the accel- 
erator urinse muscles. The urethra runs through the upper part of the 
corpus spongiosum, surrounded by a layer of erectile tissue, the part 
within the bulb being called the bulbous portion of the urethra. The 
fibrous envelope is white, thinner than that of the corpora cavernosa, and 
encloses a similar trabecular structure. Just beneath it. forming part 
of the outer coat, is a layer of muscular fibres, and a second muscular 
layer lies beneath the urethral mucous membrane. 

THE MALE URETHRA. 
Describe the urethra, and give its three divisions. 

The male urethra extends from the neck of the bladder to the end of 
the penis, is about 8£ inches long, and is lined throughout by mucous 
membrane supported by a submucous tissue and connected by it with the 
subjacent tissues in its three parts — viz. the prostatic, membranous, and 
spongy. Part of the submucous tissue is composed of a longitudinal 
muscular layer internally and a circular externally. 

The prostatic portion is the widest part of the canal, and traverses 
the prostate gland, being about If inches long, widest at the middle, and 
lying above the middle lobe. It is very dilatable. On its floor is a slight 
elevation at the back part, which passes back to the uvula vesica 1 , and 



344 ORGANS OF REPRODUCTION (MALE). 

is placed in the median line, measuring f inch long and about £ inch at 
its maximum height. This ridge has been variously named the crista 
urethras, colliculus seminalis, verumontanum, and caput gallinaginis. 
On each side of it is a groove, the prostatic sinus, the floor of which 
presents the orifices of the numerous prostatic ducts. 

In the fore part of the verumontanum is a depression, which leads 
into the sinus pocularis or uterus masculinus, upon or within the margins 
of which are the orifices of the ejaculatory ducts. This sinus forms a 
cul-de-sac running in the verumontanum and beneath the middle lobe of 
the prostate. 

The membranous portion lies between the apex of the prostate 
and the bulb of the corpus spongiosum, and is the narrowest part of 
the canal. It is f inch long. It pierces, lies between, and is invested 
by the anterior and posterior layers of the deep perineal fascia, and is 
surrounded by the compressor urethras, one of Cowper's glands lying 
on each side. 

Cowpers glands are yellowish, lobulated bodies, of the size of a pea, 
lying between the two layers of the deep perineal fascia, behind the mem- 
branous urethra, and between the arteries of the bulb above and the trans- 
verse fibres of the compressor urethras below. The lobules are made up 
of acini and joined together by fibrous tissue. The ducts from the lob- 
ules unite outside the gland into a common duct, which runs forward 
beneath the mucous membrane for about an inch and opens on the floor 
of the bulbous portion of the urethra. 

The spongy portion of the urethra is enclosed by the corpus spon- 
giosum, and is about 6£ inches long. The bulbous portion, or sinus, is 
dilated, but beyond the bulb the urethra is of uniform calibre as far as 
the glans, in which it is again dilated, forming here the fossa nacicularis. 
and its long axis becomes vertical instead of transverse. At the meatus 
it is much contracted. 

The mucous membrane presents the orifices of many small racemose 
glands (glands of Littre) and of many lacunae. *One of these latter, in 
the upper part of the fossa navicularis, is considerably dilated, and is 
called the lacuna magna. 



THE TESTES. 
Describe the spermatic cord. 

The testicles are two glandular organs suspended in the scrotum by 
the spermatic cord. 

The spermatic cord extends from the internal ring to the back of the 
testis. Its various parts are connected together by areolar tissue, and 
are invested by the various processes of the fascia, which descends with 
the testicle. In its course through the inguinal canal it lies at first 
between the internal oblique and the fascia transversalis. the former 
at times arching over it ; then between the aponeurosis of the external 



thp: testes. 345 

oblique and the conjoined tendon : and Poupart's ligament is below. 
The left cord is the longer. 

Of what is the spermatic cord composed ? 

It is composed of the spermatic artery, artery of the vas deferens, and 
cremasteric artery, the spermatic veins from the back of the testis, which 
receive the veins from the epididymis to form the pampiniform plexus, 
a number of large lymphatics, and the spermatic plexus of the sympa- 
thetic, together with the vas deferens, the layers of fascia which cover 
tin- testicle, and the remains of the peritoneal testicular process. 

What are the boundaries of the inguinal canal ? 

The inguinal canal is bounded behind by the fascia transversalis and 
the conjoined tendon ; in front by the transversalis and internal oblique 
above, and the external oblique aponeurosis below ; its floor is formed by 
the curving back of Poupart's ligament ; its roof by the arched fibres of 
the internal oblique in apposition with the aponeurosis of the external 
oblique. 

Give the coverings of the testicle. 

The testicle is covered from without inward by the following structures : 
the scrotum, composed of skin and dartos ; the intercolumnar or ex- 
ternal spermatic fascia ; cremasteric _ fascia ; infundibuliform fascia, or 
internal spermatic fascia ; tunica vaginalis. 

What is the scrotum? 

The scrotum is a pocket which contains the testicles and part of the 
spermatic cords, and is marked superficially by a median ridge, the raphe, 
which runs from the penis along the scrotum and perineum to the anus. 
The scrotum consists of a layer of skin and the dartos. 

The sfa'n is thin and dark, and presents folds or rugas, is covered with 
hairs thinly scattered, and is furnished with sebaceous glands. 

The dartos is a thin contractile tunic, of a reddish color, continuous 
with the superficial fascia of the groin and perineum ; it is ver} 7 vascular, 
and is composed of loose areolar tissue and unstriped muscle. It sends 
in a partition, the septum scroti, which separates the two testes, and is 
attached to the under surface of the penis and to the raphe. 

Give the fasciae within the scrotum. 

The intercolumnar fascia, separated by loose areolar tissue from the 
dartos, is attached to and descends from the margins of the pillars of 
the external ring. 

The cremasteric fascia consists of scattered muscular loops or bundles 
(cremaster muscle), connected together by areolar tissue, the former 
beins continuous with the lower border of the internal oblique. 

The infundibuliform fascia is continuous above with the fascia trans- 



346 ORGANS OF REPRODUCTION '(MALE). 

versalis and the subserous areolar tissue of the peritoneum. These two 
together, the latter being underneath, form the fascia propria. It in- 
vests the surface of the cord and sends in septa between its component 
parts. 
The tunica vaginalis (see Testicle proper). 

Describe the testicle proper and epididymis. 

Each testicle is ovoid, flattened from side to side, and suspended ob- 
liquely (the left being somewhat the lower), its upper end being directed 
forward, outward, and upward, the lower in the opposite direction. 
Each is 1^ inches long, 1J inches wide, and less than 1 inch thick, and 
weighs f to 1 ounce. 

The front, sides, and both ends of the testis are free, smooth, and 
covered by the tunica vaginalis. At the posterior border the vessels and 
nerves enter and emerge, and to this border, as well as to the outer sur- 
face, is attached the epididymis. 

The epididymis is a long, narrow structure, made up of a body, a 
head or globus major, and a tail or globus minor. 

The globus major is large, and joined to the upper end of the testicle 
by the efferent ducts ; the minor is small and pointed, and is joined to 
the lower end of the testicle by a reflection of the tunica vaginalis and 
some cellular tissue. The convex surface and anterior border of the 
epididymis are free and covered by the tunica vaginalis, as is also the 
concave or attached surface (except at the ends), the serous membrane 
here forming the digital fossa. On the front of the globus major are 
one or more small pedunculated bodies called the hydatids of Margagni, 
believed to be the remains of Muller's duct. The epididymis is a con- 
voluted canal whose lumen is continuous with that of the vas deferens. 

The tunica vaginalis is a closed serous sac, and consists of a vis- 
ceral layer and a parietal layer. 

The visceral layer adheres to the outer surface of the tunica albuginea, 
surrounding the testis and epididymis, and joining them together by a 
fold. It forms between them the pouch known as the digital fossa. 

The parietal layer is reflected on to the inner surface of the scrotum 
at the posterior border of the testicle. 

The tunica albuginea is the fibrous coat which surrounds the soft 
substance of the testis and is reflected at the posterior border into its in- 
terior, forming a sort of septum, the corpus Highmori or mediastinum 
testis. This septum, wider above than below, extends from the upper 
nearly to the lower end of the gland, and sends off numerous trabecule 
which join the inner surface of the tunica albuginea. These divide the 
organ incompletely into lobules. The tunica vasculosa (pia mater testis) 
is a vascular plexus supported by areolar tissue which covers the inner 
surface of the tunica albuginea and its trabecular 

The gland substance consists of seminiferous tubules, which are 
contained within the lobules above mentioned, each lobule containing two 



THE TESTES. 347 

or three seminiferous tubules. Eaeh of these latter is lined by several 
layers of epithelial eells, from which, by a process of division (karyoki- 
nesis), are finally developed the spermatozoa. 

The lobules are conical, their bases being turned toward the circum- 
ference, their apices toward the mediastinum. In the latter situation 
the tubules become straighter, and unite to form twenty to thirty large 
ducts, the tubulf recti. These tubuli recti open into a vascular network, 
the rete testis, which lies in the substance of the mediastinum, and from 
this issue twelve to twenty vasa efferentia, which pierce the tunica albu- 
ginea and enter the globus major of the epididymis, where they now 
become tortuous and form conical masses, the coni vascvlosi. 

Describe the vas deferens, the vesiculse seminales, and the ejac- 
ulatory ducts. 

The vas deferens, the continuation of the epididymis, is the excre- 
tory duct of the testicle. From the globus minor it runs along the inner 
side of the epididymis and back of the testis, and in the spermatic cord 
to the internal ring : here it descends, crossing the external iliac vessels, 
and curving around the outer side of the deep epigastric artery. It now 
passes beneath the peritoneum to the side of the bladder, and runs down- 
ward and backward to its base, internal to the ureter and across the ob- 
literated hypogastric artery. At the base of the bladder it lies between 
it and the rectum, internal to the seminal vesicle, the duct of which it 
joins (close to the base of the prostate) after having enlarged and again 
narrowed, forming with it the ejaculatory duct. Its length is about 2 
feet and its diameter about -^o inch. It has an external areolar coat, a 
middle muscular coat of two layers, longitudinal and circular, and an 
internal mucous coat covered with columnar epithelium. 

The vesiculse seminales, conical in form, the wider end looking 
backward, lie between the rectum and the base of the bladder, and are 
the reservoirs for the semen. They are 2 inches long and £ inch wide. 
In front they converge, and each joins the corresponding vas deferens at 
the base of the prostate to form the ejaculatory duct. The vesicle is a 
single tube 4 to 6 inches long, coiled up and giving off diverticula. It 
ends behind in a blind extremity, and is 2 inches long in its natural con- 
dition. 

Each ejaculatory duct is f inch long, and runs one on each side, 
forward and upward within the prostate, between its middle and lateral 
lobes, and along the walls of the sinus pocularis, close to the opening 
of which they empty. Each has an areolar, a muscular, and a mucous 
coat. 

The semen is a whitish fluid composed of liquor seminis, seminal 
granules, and spermatozoa. The granules are ^Vo inch in diameter. 
The spermatozoa consist of a head, formerly the nucleus of a spermato- 
blast, a body, and a tail. _ The spermatoblasts constitute one of the 
layers of epithelial cells lining the seminiferous tubules. 



348 ORGANS OF REPRODUCTION (FEMALE). 

ORGANS OF REPRODUCTION (FEMALE). 
External. 

THE VULVA. 
Describe the vulva. 

The term vulva or pudendum includes the mons veneris and labia, the 
nyrnphae and clitoris, the hymen or its remains, the meatus urinarius, 
and the vaginal orifice. 

Describe these various parts. 

The mons veneris is a fatty cushion covering the front of the pubes, 
and after puberty is plentifully supplied with hairs. Below, it divides into 
the two labia majora, which, diminishing in size as they pass downward 
and backward, unite an inch in front of the anus. The two extremities 
are joined, and form the anterior and posterior commissures. Between 
the latter and the anus is the perineum, and just within the posterior 
commissure is a transverse fold, the frenulum pudendi or fourchette. 
Between this fold and the posterior commissure is a triangular space, the 
fossa navicularis. 

The nymphce, or labia minora, smaller than the above, run from the 
middle of the labia majora upward to the clitoris, each dividing into two 
folds, the upper pair of which join to form a prepuce for that organ, 
and the lower two to form its fraenum. They are continuous externally 
with the labia majora, internally with the vagina, The mons veneris is 
composed interiorly of fatty and fibrous tissue ; the labia, of areolar fatty 
and dartoid tissue, with vessels and nerves ; the nyrnphae, of a plexus 
of vessels covered by mucous membrane. 

The clitoris is the analogue of the penis, consisting like it of two 
corpora cavernosa united by a septum pectiniforme, and prolonged behind 
into two crura attached to the pubic and ischial rami. It also has a sus- 
pensory ligament and a glans enclosed by the nyrnphae. Two erectores 
clitoridis muscles are attached to the crura. It has no corpus spongiosum 
nor urethra. 

Between the clitoris and the vagina, bounded on each side by the 
nyrnphae, is the vestibule, a triangular space, in which, just above the 
vagina, is the meatus urinarius, 1 inch below the clitoris. 

The hymen is a mucous fold which more or less completely occludes 
the orificium vaginae. It is generally semilunar in form, concave above, 
or it may be a complete membrane, perforate or imperforate, or it may 
be absent. After labor its remains form the carunculae myrtiformes. 

The glands of Bartholin, the analogues of Cowper's glands in the 
male, are two yellowish bodies on each side of the vaginal opening, 
each of which discharges by a single duct between the hymen and the 
nyrnphae. 

On each side of the vestible, behind the nyrnphae, is a leech-shaped 
mass, the bulbus vestibuli. Each consists of a venous plexus enclosed 



THE URETHRA. — THE UTERUS. 349 

by a fibrous capsule, and is about 1 inch long. In front of these, and 
connecting them with the vessels of the clitoris, is a small venous plexus, 
the pars intermedia of Kobelt. 

THE URETHRA. 
Describe the urethra. 

The female urethra is a mucous canal, li inches long, running down- 
ward and forward in the anterior vaginal wall from the neck of the 
bladder to the meatus. As in the male, it pierces the triangular liga- 
ment, and is surrounded by the compressor urethrae muscle. It consists 
of a muscular, a mucous, and, between them, an erectile, coat. It is 
supplied with numerous glands, and just within the meatus near the 
floor are two ducts which extend upward for about f inch. These are 
called Skene's tubules. 

THE VAGINA. 
Describe the vagina. 

The vagina extends from the vulva to the uterus, lying behind the 
bladder and in front of the rectum, and is about 4 inches long on its 
anterior wall, 5 to 5$ on its posterior, and is directed from the uterus 
downward and forward. 

Above, it embraces the cervix uteri, and its walls are flattened from 
before backward. It is narrowest at the introitus, or orificium vaginae. 
In front it is in relation with the urethra and base of the bladder; 
Inland it is connected with the anterior wall of the rectum by its lower 
three-fourths, the cul-de-sac of peritoneum (Douglas's) separating them 
above ; laterally the broad ligaments are attached above, and the leva- 
tores ani below, as well as the recto-vesical fascia. Its inner surface pre- 
sents a mesial ridge or raphe on the front and back walls, the coluinnae 
rugarum, and from them on both sides run out transverse folds or rugae. 

The vaginal mucous membrane is squamous, with papillae here and 
there. The submucous coat holds many large veins and some muscular 
fibres, making a sort of erectile tissue. The veins form a sort of plexus. 
The muscular coat comprises an internal circular and an external longi- 
tudinal layer. At the lower part is the sphincter vaginae, a muscle 
composed of striped fibres. 

The internal organs include the uterus, tubes, and ovaries. 

Internal. 

THE UTERUS. 
Describe the uterus. 

The uterus or womb is a hollow muscular organ lying in the pelvis 
between the bladder and rectum. In the virgin it is pear-shaped, 
flattened from before backward, its upper end looking forward and up- 
ward, its lower downward and backward, forming an angle with the 



350 ORGANS OF REPRODUCTION (FEMALE). 

vagina. Above, it is invested by the peritoneum, which covers its body 
before and behind ; it covers also the cervix behind, but in front the 
peritoneum is reflected on to the bladder before reaching the cervix. 
Its upper and back part is in contact with the small intestine, its lower 
and front part with the bladder, the peritoneum separating them. The 
two folds of peritoneum after investing the uterus are applied to each 
other and form the broad ligaments. 

The uterus is 3 inches long, 2 wide, and 1 thick, and it weighs about 1 
ounce. It is divided into a body, fundus, and neck. The fundus is 
the convex part above the entrance of the tubes ; the body is the part 
between this and the neck. In front of the Fallopian tubes, at the up- 
per part of the lateral borders, the round ligaments are attached, and 
below and behind them are the ligauienta ovarica. The cervix is the 
lower constricted, rounded part, and around it is attached the vagina. 
At its vaginal end is a transverse opening, the os uteri, the posterior lip 
of which is thin and long, the anterior thick. 

Describe the cavity of the uterus. 

The cavity of the uterus is small ; that part within the body is tri- 
angular, flattened antero-posteriorly, and presents at the superior angles 
the openings of the Fallopian tubes; also, at its junction with the neck 
it is constricted to form the os internum or isthmus. The cavity of the 
cervix is barrel-shaped and flattened antero-posterioriy, presenting on 
each wall a longitudinal column sending off oblique rugae on each side ; 
hence its name, arbor-vitae uterinus. 

Give the structure of the walls of the uterus. 

The walls of the uterus consist of an outer serous coat (already de- 
scribed), an inner mucous, and an intermediate muscular. The muscular 
coat forms the bulk of the uterus, and consists of bundles and layers of 
unstriped fibres which interlace, and of some areolar tissue supporting 
them, and of blood-vessels, lymphatics, and nerves. Three layers are 
described — an external transverse layer, some of the fibres being con- 
tinued on to the Fallopian tubes, etc. ; a middle layer of intermixed 
longitudinal, oblique, and transverse fibres ; and an internal layer, which 
is circularly arranged at the cervix, forming the so-called external and 
internal sphincters. This layer is the muscularis mucosae of the mucous 
membrane. 

Describe the mucous membrane of the uterus. 

The mucous membrane of the body differs from that of the cervix. 
The former is smooth, reddish, with columnar cells, and presents the 
ducts of a number of tubular glands which end by blind, sometimes 
forked, extremities. In the cervix it is firmer, and presents numerous 
saccular and tubular glands between the rugae of the arbor vitae, and. 
below, numerous papillae. The glands are sometimes distended by their 
Secretion, the ducts being choked, and present the appearance of vesi- 



THE FALLOPIAN TUBES. — THE OVARIES. 351 

cles ; hence their name, ovules of Naboth. At the upper part of the 
cervix the cells are columnar and ciliated ; below, stratified. 

What are the ligaments of the uterus ? 

The ligaments of the uterus are the round ligaments and several 
peritoneal folds — namely, two each in front, behind, and laterally. 

The round ligaments are two cord-like bundles of areolar, fibrous, and 
plain muscular tissue, with vessels and nerves, covered b.v peritoneum, 
which run from the upper angle of the uterus to the internal ring. 
Each then runs through the corresponding inguinal canal to end in the 
mons veneris and labia. Each measures about 4 or 5 inches in length, 
and their direction is upward, forward, and outward. The peritoneum, 
which invests them, is sometimes prolonged (as in the foetus) for some 
distance into the inguinal canal, and forms the canal of Nuck. Gene- 
rally this canal is obliterated. 

The anterior or vesico-uterine ligaments stretch between the bladder 
and the uterus ; the posterior, between the uterus and rectum, hence 
called the recto-uterine, forming a pouch, the cul-de-sac of Douglas. 

The two lateral or broad ligaments pass from the sides of the uterus to 
the sides of the pelvis, thus dividing the latter into two parts. They 
are formed by the coalescence of the peritoneal layers investing the ante- 
rior and posterior surfaces of the uterus, and contain between the two 
layers : the Fallopian tube at the upper margin ; _ the round ligament be- 
low and in front of the tube ; the ovary and its ligament enfolded by the 
posterior layer ; and the uterine blood-vessels, lymphatics, and nerves. 

THE FALLOPIAN TUBES. 
Describe the Fallopian tubes. 

The Fallopian tubes, or oviducts, run from the upper angles of the 
uterus toward the sides of the pelvis, and near their termination bend 
downward, backward, and inward. They are 3 to 4 inches long, are at 
first narrow, then enlarge near the extremity (ampulla), and end in a 
fimbriated margin, one of the fimbriae being attached to the ovary. The 
canal is very narrow at the uterine end (ostium uterinum), begins to 
widen in the outer half to form the ampulla, and at its termination again 
narrows (ostium abdominale). 

The tubes consist of a peritoneal coat, a muscular coat composed of 
internal circular and external longitudinal fibres, and a mucous coat. 
The latter is continuous with that of the uterus and with the perito- 
neum, the epithelium being ciliated columnar, and it is thrown into lon- 
gitudinal wrinkles, more marked in the outer half of the tube. 

THE OVARIES. 
Describe the ovaries. 

The ovaries are analogous to the testes, and are flattened, oval bodies, 
measuring 1 £ inches long, § inch wide, and h inch thick, each weighing 



352 ORGANS OF REPRODUCTION (FEMALE). 

60 to 100 grains. Of each, the two sides are free as well as the convex 
border, the straight border (hilus) being attached to the broad ligament 
and admitting the vessels, etc.^ Its outer end is attached by the fimbria 
ovarica to the Fallopian tube, its inner end to the uterus by the ligament 
of the ovary, a dense, fibro-muscular cord attached to the uterus below 
and behind the tube. 

The ovary consists of a stroma in which are imbedded the Graafian 
follicles, and of a covering of columnar cells, the germinal epithelium. 
The stroma is invested beneath the epithelium by a dense fibrous layer, 
the tunica albuginea, and consists of connective tissue with numerous 
cells, as well as of elastic fibres, with some muscular tissue and blood- 
vessels. 

The Graafian follicles consist of an external fibrous coat, and beneath 
it a coat called the ovi-capsule, lined internally by a layer of cells, the 
membrana granulosa. Within this last-named layer is the ovum, in- 
vested by the discus proligerus, a layer of cells derived from the mem- 
brana granulosa, together with the liquor folliculi. 

For the structure of the ovum see Histology, or Gynecology, or Ob- 
stetrics of this series. 

THE PAROVARIUM. 

What is the parovarium ? 

The parovarium, organ of Rosennriiller. is a foetal remnant lying in 
the broad ligament between the ovary and Fallopian tube. It consists 
of several vertical tubes, lined by epithelium, whose lower ends run 
toward the hilus of the ovary, and whose upper ends are united by a 
horizontal tube, the duct of Graertner. 



THE MAMMARY GLANDS. 
Describe the mammary glands. 

These are accessory to the generative system and secrete the milk. 
They are two rounded eminences, one on each side of the thorax, between 
the sternum and axilla and the third and seventh ribs. Just below the 
centre is a conical eminence, the nipple, which is dark, and is surrounded 
by a pinkish areola which darkens in pregnancy. < It presents the orifices 
of the lactiferous ducts, and consists of vessels mixed in with plain mus- 
cular fibres, and by friction may be made to undergo erection. 

The mamma consists of a number of lobes separated by fibrous tissue 
and some adipose tissue. _ The lobes are divided and subdivided into 
smaller lobules, which are in turn made up of alveoli. Each lobe has an 
excretory (galactophorous) duct, and these, about sixteen in number, 
converge to the areola, there dilating into ampuUce or sinuses. They 
then become smaller again, and, surrounded by areolar tissue and ves- 
sels, pass through the nipple to empty on the surface by separate orifices. 



GLOSSARY. 



F. = French; Gr. = Greek : L. = Latin; N. L. = New Latin; adj. = adjective; c. = 
common; dim. = diminutive ; f. = feminine ; m. = masculine ; n. = neuter or 
noun ; part. = participle. 



Abdo'men, inis, n. (L.) = venter. [Etymology doubtful. Andrews: Adipomen, 
from adeps, fat, lard, the fat lower part of the belly ; Foster : Abdere, to 
conceal, and omen, either a sign in ancient augury or a contr. of omentum — 
that which conceals the omen or omentum. This explanation of omen 
does not commend itself; men is a formative ending, the whole word 
meaning ''the concealer."] The belly, paunch. 

Acerv'ulus, i, m. (L.) (aserv'ulus) [dim. of deervus, i, m., a heap ; root ah, per- 
haps related to agitate, to drive]. A little heap; applied to a collection 
of "brain-sand" in the pineal gland. 

Acetab'ulum, i, n. <L.) [ace'tum, vinegar]. A vinegar vessel, hence any cup- 
shaped vessel. The articular cavity of the innominate bone. 

Adminic'ulum, i, n. (L.) [ad, manus, upon the hand]. The stake around which 
the vine twines. A support. 

Afferent [afferens, part, from ad, to, ferre, to carry]. Conveying something 
from the periphery to the centre. 

Ag'ger, eris, m. (L.) [aggerare, to heap up]. A heap or prominence. 

Alve'olar (not alveolar). Pertaining to or containing alveoli. 

Alve'olus, i, m. (L.) [dim. of alveus, a hollow]. Bone-socket for a tooth ; an 
air-cell ; a part of a gland. 

Anal'ogous [dvd, A6yo?, according to due ratio]. Referring to a part in one 
organism which has the same function as another part in another organ- 
ism; similarity of purpose. " When organs in different animals agree in 
structure they are 'homologous ;' when they perform the same functions, 
they are 'analogous.' The wing of a bird and arm of a man are homolo- 
gous, not analogous; the wing of a bird and the wing of an insect are 
analogous, not homologous." 

Anas tomo'sis, is, f. (L.) [dvd, of each, <ttoju6w, to furnish with a mouth, to 
contract to a narrow mouth, to whet the appetite]. The communication 
of an artery or vein with another artery or vein. 

Anat'omy [avd, apart, Te/xveiv, to cut]. A science of the structure of organized 
bodies. 

Anco'neus, a, urn, adj. or n. m. (L.) [ancon, onis, m. = ayK<*n>, the bend of the 
arm]. Any muscle connected in any way w T ith the olecranon; now 
applied to one muscle connected with the triceps and olecranon. 

Annec'tant [annecto, ad, to, necto, I fasten together]. Connecting. Applied to 
brain-tissue that connects adjacent gyri. 

Anti'cus, a, um, adj. (not an'ticus) (L.) [ante, before]. Anterior. 

Aor'ta, ae, f. (L.) [deprrj, in Hippocrates the bronchi ; from &eip<o, I lift or 
heave]. The common trunk of the systemic arteries. 

Apoph'ysis, is, pi. es, f. (L.) (apof'isis) [anoQvia]. An outgrowth. 

Aq'ueduct (L. aquseductns, us, m.) [aqua, water, ducere, to lead]. A canal ; it 
may or may not contain fluid. 

23— A. 353 



354 GLOSSARY. 

Arach'noid, adj. and n. (arak'noid) (L. arachnoid' ens) [dpdxvy, a spider's web, 
elSo?, resemblance]. The middle of the three membranes investing the 
brain and spinal cord. 

Are'olar (not areo'lar) [are'bla, <t, f. dim. of a re 1 a, an open space]. Pertaining 
to a tissue containing interspaces. 

Ar'tery (L. arte'Ha, se, f. Gr. dprripia) [from dpT>?p, that which suspends; origi- 
nally applied to the trachea, called the "rough artery,'' rpaxela dprqpia, 
suspending the lungs; perhaps from djjp, ie'po?, air, Trjpew, I convey. The 
ancients believed it contained air, being found empty after death]. A 
vessel which conveys blood from the heart. 

Aryte'noid (L. arytsenoid'eus, from arytx'na) [dpvraiva, a ladle or pitcher, eI5o?, 
resemblance]. Shaped like the mouth of a pitcher. A cartilage of the 
larynx. 

Aste'rion, ii, n. (L.) [atmjp, star]. A sort of spider ; point of junction of pari- 
etal, occipital, and temporal bones. 

Astrag'alus, i, m. (L.) [acrrpayaAos, a cervical vertebra; darpdyakoi were dice 
made of the cubical ankle-bones; Lat. tali were stone dice]. The ankle- 
or sling-bone, the first of the tarsus. 

Az'ygos, n. and adj. [a, without, C,vy6v, yoke]. Without a fellow; unyoked. 

Basil'ic [L. basil' icus ; Gr. /Sao-iAiKos, royal, from /3ao-iAet;?, king; perhaps from 
Arabic al-basilik, the inner], A superficial vein of the arm. The name 
was applied by the ancients to important parts. The right basilic vein 
was called hepatic, as it was supposed to have some connection with the 
liver; for a similar reason the left basilic vein was called the splenic ; the 
cephalic veins were thought to be connected with the head, and whenever 
the liver, spleen, or head was diseased, venesection was performed on 
the appropriate vein. 

Bifur'cate (not bi'furcate) [bis, twice, furca, se, f., a two-pronged fork]. To 
divide into two branches. 

Blast'oderm [/SAaen-o?, a germ, Sep^a, skin]. A membranous bag from which 
the embryo is formed. 

Breg'ma, atis, n. (L.) [ppe X ei.v, to moisten, because the part is soft and moist in 
infants]. Junction of coronal and sagittal sutures. 

Cal'amus, i, m. (L.) [*dAap.o?, a reed or cane; a reed-pen], C. scriptorius, 
writing-pen. A portion of the fourth ventricle, shaped like a pen. 

Cal'yx, cal'ycis, m. (L.) OaAvVro), I cover]. A cup. The outermost leaflets of 
a flower; a cup-like subdivision of the ureter. 

Canine' (kayneyn'), L. caninus [cams, a dog]. Pertaining to or resembling 
some structure in a dog. 

Canthus, i, m. (L.) [= KdvOos, the tire of a wheel]. The angle of juuction of 
the upper and lower eyelids. 

Capillary (kap'illary preferable to kapil'lary) [capillus, i, m or um, i, n., hair 
of the head, dim. of root cap (caput)]. Pertaining to hair or hair-like 
filaments. 

Carot'id (L. carb'ticus) [Kapwn'Ses (pi.), the carotids, from *dpo?, a deep, heavy 
sleep, from the fact that drowsiness can be produced by compression of 
these arteries in the neck]. 

Caruncula, ae, f. (L.) [dim. of caro, camis, f. flesh], A little piece of flesh; 
caruncle. 

Cer'ebral (not cere'bral) [L. cerebra'lis]. Relating to the brain. 

Cer'ebrum, i, n. (L.) (not cere'brum). The brain as a whole ; the principal 
part of the brain, including the hemispheres. 

Cervi'cal (not cer'vical) [cervix, cervi'cis, f., neck; L. cervica'lis]. Pertaining 
to the neck ; neck of uterus. 



GLOSSARY. 355 

Cervix, cervi'cis (servi'sis), gen. pi. cer'vicum, f. (L.) Neck, including t he 
nape. 

Chias'ma, chias'matis, n. (L.) (kiaz'ma) [xiaana, from x«x£w, to mark with *]. 
The crucial union of parts. 

Circumvallate [circum, around, vallare, to surround with a rampart]. Sur- 
rounded witli a prominence. 

Cli'toris (not klit'oris), clitor'idis, f. (L.) [/cAen-opi?, Kkeiropi&iv, to titillate, or 
from K-Weu', to shut up, or from kAtjttjp, a servant who invites guestsj. A 
small erectile organ in the vulva, hoinologue of the penis. 

Coccygeal (koksy'eal, not koksige'al) (L. coccyg'eas). Pertaining to the coc- 
cyx or tail. 

Coc'cyx (kok'siks), gen. coccy'gis (not coc'cygis) (L.) [k6kkv£, a cuckoo, whose 
beak it resembles]. The caudal end of the spinal column. 

Coe'liac (see'liak) [xoiAiaKos from KoiAi'a, the belly]. Eclating to the abdomen 
or its viscera. 

Com'es, com'Ttis, m. or f. (L) [cam, with, eo, I go]. A companion. 

Con'dyle, L. cqndylus, i, m. (con'dil) [k6vBv\o<;, a knot]. An articular process. 

Con'jugal [conja.v, ugis, c. spouse ; con, together, jungo, to yoke]. Lig. conju- 
gate, united with its fellow. 

Conniven'tes, adj. pi. (L.) [connivens entis, from con-mveo, I wink]. Folding 
on each other (valvulae c). 

Coro'nal (not cor'onal) [cord' no, ve, f. Kopuvr], crown]. Relating to a crown. 

Cran'ium, ii, n. (L.) [xpai-o?, helmet, or from upaviov, skull]. The brain-case; 
the entire skull. 

Cremas'ter, cremaster'is, m. (L.] [Kpe/xaor^p, a suspender, Kpep.dvwixi, I let hang 
down]. The suspensory muscle of the testicle. 

Crus'ta, se, f. (L.) crust, outer coating. Ventral portion of the crus cerebri. 

Cu'bitus, i, m., or cu'bitum, i, n. (L.) [cubo, I lie down, kv^ltov]. Elbow 
(serving for leaning upon); ulna; forearm. An ell or cubit (originally 
the distance from the elbow to the end of the middle ringer ; the Roman, 
17^ inches : the English, 18 inches; the Hebrew, 22 inches). 

Cu'neiiorm. [cuntius, i, m. wedge, forma, form]. Wedge-shaped. 

Decus'sate (not de'cussate) [decas'sis, is, m. (decem-as), a ten-as piece, a coin; 
as was a pound weight, or 16?r cents. As the Roman numeral on the 
coin was X, decassis came to mean the intersection of two lines]. To 
cross; to place in the form of an X. 

Di'aphragm [dy'afram), L. diaphragma, atis, n. (dyafrag'rna) [8id<f>payixa, a 
partition-wall; Bid, thoroughly, ^pdacrm, I fence in]. A partition between 
cavities. The partition between the thoracic and abdominal cavities. 

Diapb/ysis, is, f. (diaf'isis) (L.) [Sid, between, <f>ven>, to grow]. The part of 
bone formed from the principal centre. 

Digas'tric [Si's, twice, yaarrip, belly; L. biventer]. Having two bellies. 

Duode'num, i, m. (L.) [duodeni, twelve each]. Upper portion of the small 
intestine, about 12 finger-breadths (10 inches) long. 

Efferent [efferens, part., ex, from, ferre, to carry]. Carrying or leading from 
an organ. 

Em'bryo, o'nis (L.) [k^pvov, eV, within, /3pvw, to be full of anything]. The 
fecundated ovum in the first two or three months of its development. 
(See Fcetus. ) 

Em'issary [e, out. mittere, to send]. Serving as an outlet. 

Ephip'pium (effip'pium)), ephip'pii, n. (L.) [iiri, upon, mtjtos, horse]. A sad- 
dle ; a part of the sphenoid bone. 

Epiphysis (epifisis), is, f., pi. Epiph/yses (L.) [eir(, upon, <j>veu; to grow]. 
The portion of a long bone from a secondary or tertiary centre. 



356 GLOSSARY. 

Epiploic (L. epiplo'icus, a, um, adj.) [eniir\oov, omentum, en-f, upon, 7r\eo>, I float]. 
Pertaining to the omentum. 

Epipter'ic (epipter'ik) [e«rt, upon, mepov, wing]. Situated on the greater wing 
of the sphenoid. 

Eustach'ius (Bartholomeo Eustachi), of the Italian school (1500), was the con- 
temporary of Vesalius, and divides with him the merit of creating the 
science of anatomy. He studied especially the internal car. 

Excre'tory [ex, out, cerno, I choose]. Pertaining to excretion (the separation 
from the body of parts supposed to be useless). 

Fac'et (not faset') (F.) [dim. of face]. A small face. 

Fallopius was a pupil of Vesalius, and professor at Padua in 1551 ; studied 
bones^especially the internal ear and organs of generation. 

Ferrugin'eus, a, um, adj. (L.); also ferrug'inus [ferrugo, iron-rust, from fer- 
rum, iron]. Of the color of iron-rust; dusky. 

Foetus, us, m. (strictly fetus) (L.) [from root feo, whence also fecundus and 
felix, fruitful ; femiua, fruit-bearer; fenus, interest or gain]. The unborn 
child. In the human subject this term is usually applied to the embryo 
only after the third month of gestation. 

Fontanelle (fontanel') (F.) [foutaneUa, se, f., dim. of fons, fontis, a fountain]. 
A membranous interspace between fcetal skull-bones. Pulsation like a 
fountain is here seen. 

Fo'vea, ae, f. (L.) [fodio, ere, to dig]. A small pit, a pitfall. An old term for 
the vulva. 

Gal'ea, ae, f. (L.) [yaAo?, weasel, from the skin of which helmets were made]. 
Helmet ; the amnion. 

Ga'len, L. Claudius Galenus [yaAavo?, calm]. The greatest anatomist of antiq- 
uity, lived in Pergamus and Rome; died, set. 90, in 193 A.D. Wrote in 
Greek; he described the bones and sutures of the cranium, the vertebne, 
the thorax, nearly in the same manner as at present. He described the 
facial, maxillary, and neck muscles, naming one the platysma mi/aides. 
He proved that arteries contained blood, not air. His death marked the 
downfall of ancient anatomy. 

Gallinag'o, gallinag'inis, f. (L.) [galli'na, se, hen]. The wood-cock. Caput 
gal., syn. of verumontanum. 

Glabella, ae, f. (L.) [glabellas, a. um, dim. of glaber, smooth, without hair]. 
The part of the frontal bone between the superciliary ridges. 

Glans, glandis, f. (L.). An acorn. Any object resembling a nut, as the head 
of the penis or clitoris, a suppository, a pessary, a goitre. 

Hal'lex, hal'licis, or allex, allicis, m. (L.) [aAAo/uai, to leap]. The great toe or 
thumb. (There is no authority for hallux, hallucis ; hallus or alius, kin dr. 
with allex, has the gen. alii. Alex, alecis, f. and m., fish-brine or sedi- 
ment.) 

Helicotre'ma, helicotre'matis, n. (L.) [eAif, helix, spiral, rp^a, hole]. An 
aperture at the apex of the cochlea. 

Hemorrhoid'al [hseinor'rhoi's, idis, f., ai^oppot'?, usually in pi. supply ^Ae'/Se?, 
veins; atp.a, blood, pew, I flow, run]. Pertaining to hemorrhoids. 

Heroph/ilus, i, m. [epm, hero, <f>i\eu, I love]. An anatomist of the Alexan- 
drian school, 304 b. c. He described the venous sinuses, and first applied 
the names duodenum, choroid, and calamus scriptorius. 

Hi'lum, i, n. (L.), hilus, i, m. (N. L.) [from nihilum = nihil, nothing, a trifle]. 
The black spot on the base of a bean. The point, depressed or elevated, 
of an organ where the vessels and nerves enter it and its excretory duct 
leaves it. 

Hippocam'pus, i, m. (L.) [in-TroKa/xTro?, itttto?, horse, ko/atttw, I bend; a monster, 



GLOSSARY. 357 

witli a horse's body and fish's tail, on which the sea-gods rode]. Sea- 
horse; projection of white matter into the lateral ventricle of the brain. 

Hippoc'rates, is, m. ['in-n-oKpaTTj?, in-n-o?, horse, Kparos, strength, control]. A 
Greek physician of Cos, the father of medicine, 460-377 b. c. 

Homologous [ojuos, common, A6yos, understanding]. Like a given standard ; 
constructed on the same plan. (See Analogous.) 

Impar, aris (L.) adj. [im, negative, par, equal]. Unequal, odd. 

I'mus, a, um, adj. (L.) [infUrus, that is below; inferior, lower; informs or 
imus, lowest, last]. Lowest. 

Incisi'vus, adj. and n. (L.) [in, csederefto cut into]. Incisive; a muscle near 
the incisor teeth. 

Ingrassias, John Philip, 1545-80, a Sicilian physician, made osteology a spe- 
cialty ; described the sphenoid and ethmoid, and first described the stapes. 

In'ion (N. L.) [iviov, back of the head]. External occipital protuberance. 

Intes'tine (L. intesti'nxm, i, n.) [intus, within ; cf. eVrepoy, from ivros, within]. 
The canal from the stomach to the anus. 

Ischiad'icus, a, um, adj. (L.) [iaxiaSiKds, subject to pains in the loins, iaxi-ov, 
hip-joint]. That has gout iu the hip. Pertaining to the ischium. (See 
Sciatic.) 

Ischium, ii, n. (is'khim) (L.) [Itrxiou, hip-joint, from 1<x\voj, I am strong, or 
from lo-x"*, I hold, I stop; supporting the trunk when seated]. The 
lower part of the os innominatum. 

Jeju'num, neut. sing, of jeju'nus, a, um, adj. (L.). Fasting, hungry. The 
upper two-fifths of the small intestine below the duodenum ; so called 
because it was supposed to be empty after death. 

Ju'gular (not jug'ular) (L. jugularis, e) [jugulum, i, n., the throat, dim. of 
jugum, the yoke, which was attached there]. Pertaining to the neck or 
throat. 

Laryn'geal (not larynge'al). Pertaining to the larynx. 

Lateralis, e (L.) [lotus, eris, n., the side]. Pertaining to the side (external, 
Henle). 

Lig'ula, se, f., and Lin'gula, ae, f. (L.) [dim. of lingua, tongue]. A little 
tongue. Ligula is applied to white matter bounding the floor of the 
fourth ventricle. 

Malar [mala, se, f., cheek-bone]. Pertaining to the cheek-bone. 

Malle'olus, i, m. (not malleolus) (L.) [dim. of malleus, mallet]. The project- 
ing lower extremity of the tibia or fibula. 

Malpighi, middle of seventeeth century, is the founder of histological anat- 
omy, as he used the microscope. His name is associated with the deeper 
layer of the skin and the bodies in the kidney and spleen. 

Masse'ter, eris, m. (not nias'seter) (L.) [p-ao-o-rjTrjp, from ^aado^ai, I chew]. 
(See Maxilla.) Name of a muscle of the lower jaw. 

Maxilla, se, f. (L.) [dim. of mala, se, f., the jaw or cheek, from mando, from 
/aao-ao^ai, I chew, akin to flaw and juao-crw, I knead]. The jaw-bone. The 
upper jaw-bone, the low T er being the mandible. 

Medial'is, e (L.) [medius, middle]. Pertaining to the median part (internal, 
Henle). 

Mediasti'num, i, n. (L.) [mediasti'nus is the same as medius, and more elegant 
than that short adj. ; it is not a corruption of per medium tensum, some- 
thing stretched between (Hyrtl)]. A partition. Properly the cavum 
mediastini. 

Med'ullary (rued'ullary preferable to medullary) [medulla, se, f., pith, medius, 
in the middle]. Pertaining to medulla or marrow. 

Menin'geal (not meninge'al). Pertaining to the meninges. 



358 GLOSSARY. 

Mes'entery [/uetreiTepop, ^eao?, middle, evrepov, intestine]. A fold of peritoneum 
by which the jejunum and ileum are attached to the abdominal wall; a 

ibid by which any organ is attached. 
Modiolus, i, in. (L.) [dim. of modius, a peck]. The hub of a wheel; the cen- 
tral axis of the cochlea. 
Mus'cle [dim. of nuts, muris, a mouse, museulus, a little mouse, as muscles were 

said to resemble flayed mice ; more probably from n.vhv, to close]. Animal 

tissue composed of contractile fibres. 
My'lo- [iJiv\r), a mill, from ^iW, /xii^, to make the sound p.v fxi> with closed lips, 

to murmur]. Referring to the jaw, especially the lower, or to the molar 

teeth. 
Myoi / des [mus, muscle, elfios, resemblance]. Like a muscle. 
My'otomes (L. pronunc. myot'mes) [/au? (^uiu, to keep close), a muscle, tom^, 

a section, from tcmvoj]. A series of dark paired masses on each side of the 

notochord, producing the muscular segments of the body; pro vertebrae ; 

mesoblastic somites. 
No'ni, gen. sing, of nonns, a, um, adj. (L.) [for novenus, from norem, nine]. 

Of the ninth; referring to the hypoglossal or ninth cranial nerve (old 

classif.). 
Nu'cha, ae, f. (L.). The hinder part or nape of neck. 
Obe'lion (N. L.) [6£eA6s, a spit, obelisk; a horizontal line with a point above 

and one below, -v-, was used to point out superfluous passages (kindr. with 

6|3oA6s, a coin)]. A point in the sagittal suture between the parietal 

foramina. 
Oph/ryon (off'rion) (N. L.) [6c/>pv?, eyebrow; L. supercilium]. Where the supra- 
orbital line crosses the median line. 
Opis'thion (N. L.) [bnia0to<;, hinder part]. Middle of posterior margin of the 

Jbramen magnum. 
Oppo'nens, entis (not op'ponens) (L.) [part, from ob, against, and pono, I 

place]. Standing against ; opposing. 
Os, ossis, pi. ossa, n. (L.). Bone. Os, oris, pi. ora, n. (L.). Mouth. 
Palpebral (not palpebral) (L. palpebra'Us) [pal'pebra, «, f., or pal'pebrum, i, n., 

an eyelid]. Pertaining to the eyelid. 
Papyra'ceus, a, um, adj. (L.) [papyrus, i, m. or f., TrdTrvpos, an Egyptian rush 

or flag, from the inner rind of which paper was made]. Like papyrus or 

paper. 
Pectin'eus (not pectine'us), adj. and n. (L.) [pecten, inis, m., a comb, the hair 

of the privates]. Name of a muscle rising from the os pubis. 
Peritonse'um and Peritoneum, i, n. (L.) = nepiTovaLov and ntpnoveiov [nepi, 

around, reiVw, I stretch]. A serous membrane stretched over the abdom- 
inal viscera and lining the abdominal cavity. 
Pilas'tered [pilas'ter (pila, a pillar) is a square pillar inserted into a wall, 

projecting a little from its surface]. Furnished with pilasters. 
Pi'neal [pi'nea. x, f., pine-cone]. Resembling a pine-cone. 
Platys'ma (L.) [nXdTvcrna, anything spread out, from nKdrv;, wide]. A muscle. 
Poplit'eal (not poplite'al) [poples, popltiis, m., ham of the knee (posterior part 

of knee)]. That which relates to the ham. 
Por'ta, ae, f. (L.) [root por, a place through which things are carried]. A gate ; 

the part of the liver where vessels enter as by a gate. ( Vena portse, not 

vena porta.) 
PostT'cus, a, um, adj. (L.) [post, behind]. That which is behind; posterior. 
Pre'puce (L. prmputium) [np6, before, 7t6o-0jj, penis (?)]. The foreskin. 
Process (prfic'es; pro'cess accord, to Lat. quantity) [prdcedere, to go forth]. 

A prominence or projecting part. 



GLOSSARY. 359 

Pros'tate \np6, before, 'io-t^i, I stand]. A gland situated before the neck of 
the bladder in the male. 

Pter'ion (ter'ion) or Pte'ron (X. L.) [n-repo.-, a feather or bird's wing, from 
TreTOfxai, I fly]. Sphenoparietal suture. 

Pu'bes, pu'ber, pu'bis, eris, adj. (L.). That is grown up, adult. Pu'bes, is, f. 
The signs of manhood — i. e. the hair of the privates or the beard; the 
privy parts. Os pubis, the bone of the pubes (gen. case). 

Pyram'idal ( L.pyramidal'is, e), adj. [irvpap.Lt, 1S09 ( probably Egyptian ). Ancients 
derived it from nip, flame, because of its pointed shape; also from nvpos, 
wheat, as if pyramids had been granaries]. Shaped like a pyramid. 
Name of two muscles. 

Ra'nine [rana, se, f., a frog, a swelling under the tongue]. Frog-shaped. 
Applied to certain vessels of the tongue. 

Raph'e (raf'e) (N. L.) [pafy-n, a seam, pan™, I sew]. A ridge or suture. 

Rhomboid'eus, adj. or n. (L.) [p6/t*/3os, a figure whose sides are equal, with two 
acute and two obtuse angles; elSos, resemblance]. A muscle of the back. 

Ri'ma, ae, f. (L.) [rigma, from ringor, I open the mouth]. Chink, fissure. 

Sagit'tal (not sag'ittal) [sagit'ta, se, f., arrow]. Resembling an arrow. Per- 
taining to a vertical mesial plane of the body or any plane parallel to it. 

Saphe'nous [<ra<H?, distinct, manifest]. Applied to some superficial veins of 
the lower extremity, to nerves, and to an "opening." 

Scala, se, f. (L.) [scando, Ire, I climb]. A staircase ; a ladder. 

Scanso'rius, a, urn, adj. (L.) [scando, scansum, I climb]. Of or for climbing. 

Sciat'ic (syat'ik) (contraction of ischiatic) [laxi-ov, strictly the acetabulum; 
the haunch or hip. Prob. from io-x u 's> strength]. Related to or connected 
with the ischium. 

Secre'tory [se, aside, ceruo, I choose or put]. Pertaining to secretion (the sepa- 
ration from the blood of parts supposed to be useful to the animal economy ) . 

Sinister, tra, trum, adj. (L.) (obs. sinis'ter). On the left baud ; left. (In 
the Roman sense lucky ; in the Greek sense unlucky. In consulting aus- 
pices the Romans turned the face to the south, and so had the eastern or 
fortunate side to the left; while the Greeks, turning to the north, had it 
on their right.) 

Sol'eus, i, m. (L.) [solea, <e, f, the sole of a shoe, sandal]. A muscle of the 
calf of the leg ; named from its shape. 

Somat'opieure [<rlbp.a, body, nkevpd, a rib, the side, lining membrane of the 
chest]. Outer leaf of blastoderm, producing the body-walls. 

So'mites (L.) (L. pronunc. so'mi tes) [<r<ap.a, o^aTo?, body]. Segments of the 
body or mesoderm. 

Splanchnology [(nr\6.yxvov, pi. a, viscera, Aoyos, treatise]. The part of anatomy 
relating to viscera. 

Splanch'nopleure [<nr\dyxvoi>, viscera, inward parts, nkevpd, the pleura]. Inner 
leaf of the blastoderm, forming the alimentary canal. 

Sple'nic [splen, splenis, m., also lien, enis, m. ; a-nkqv, r)u6<;, the milt, spleen]. 
Relating to the spleen. 

Sple'nium, ii, n. (L.)- [<rn\r)v, spleen]. A patch, pad (because like the spleen 
in shape). 

Sple'nius, a, um, adj. or n. (L.) [a-nk^vLov, a bandage, compress; cm\rji>, o-ttAjjco?, 
spleen], A muscle of the back and neck, said to resemble in shape the 
spleen of certain animals. 

Stapedius, ii, m. (L.) [std'pes, std'pedis (sto,I stand; pes, pedis, a foot), stir- 
rup]. A muscle of the middle ear attached to the stapes. 

Stephan'ion (N. L.) [<ne(}>avo<;, crown, from o-Te$a>, I encircle]. The point where 
the coronal suture crosses either one of the temporal lines. 



360 GLOSSARY. 

Sutu'ra, ae (not soot'ura), f. (L.) [mo, I sew or stitch]. Suture; a dovetail 

joiut; an immovable articulation. 
Syl'vius, Jacobus (Jacques Dubois), 1478-1555 a.d., was of the French school, 

and taught anatomy in Paris. He was coarse, envious, and jealous, made 

no original research, but acquired a great reputation. Parts of the brain 

bear his name. 
Synchondrosis, pi. es (N. L.) [ avv, with, x 6 ^p°^, cartilage]. Union of bones 

by means of cartilage. 
Syn'desmo'sis, pi. es (N. L.) [<rvv, with, 8e<r/u.ds, band (Sew, I tie]. Union of 

bones by means of ligament. 
Tae'nia, ae, f. (L.) [roina, a band; retro, to stretch]. A band, ribbon, fillet; a 

tape-worm. 
Ta'lus, i, m. (L.) [a die made of knuckle-bones, marked on four sides]. 

The ankle; the heel; the astragalus. 
Tentorium, ii, n. (L.) [tendo, Tet'ro, I stretch]. A tent; the dura mater, 

which covers the cerebellum. 
Tes'ticle [testic'ulus, dim. of testis, is, m. ; pi. testes ; a witness, because the 

testicles are witnesses of manly vigor]. A glandular organ in the scrotum 

which secretes sperm. 
Thal'amus, i, m. (L.) [0aA aj uo?, an inner room, a bed. bridal-chamber, a den]. 

A central ganglion of the brain. 
Thy'roid or Thy'reoid [0upeo?, an oblong shield, from 0v P a, a folding-door, «I«os. 

resemblance]. Applied to a cartilage of the larynx, also to a gland and 

various vessels. 
Trache'a (L. pronunc.) (L. trachia) [rpaxela, from Tpa^u's, rough]. The wind- 

pipe. 
Tri'gone (try'gohne) (F.) [from trigonium, ii, n. = rplyoavov, rpet's, three, yuvia, 

corner]. A triangle. 
Trique'trus, a, urn (trykwee'trus) (L.) [ires, three]. Having three corners. 
Tritic'eus, a, um, adj. (L. ) [from triticum, n., wheat, from tero, I rub or grind]. 

Like a kernel of wheat. 
Troch'lea, ae, f. (L.) (trok'leah) [tpoxo? (rpexw), a runner, anything round or 

circular]. A pulley; a surface grooved like a pulley. 
Tym'panic (not tympan'ic) [rvunavov, a kettle-drum, tv'ttto), I beat]. Refer- 
ring to the tympanum, ear-drum. 
Umbili'cal (not umbil'ical). Relating to the navel. 
Umbili'cus, i, m. (L.) [bp.4>a.\6<;, navel, akin to ap.pu>v, umbo, boss of a shield]. 

The navel ; the centre. 
TJ'rachus, i (N. L.) (not urak'us) [ovpov, urine, ex eiv j to hold]. A band from 

the bladder to the umbilicus ; in the fcetus extended to the allantois. 
Ure'ter (not u'reter), eris (N. L.) [ovp-qrrip = ovp^Bpa, from ovprju, I make water]. 

The excretory canal from the kidney to the bladder. 
Vagi'nal (not vag'inal) [vagina, se, f., a sheath]. Relating to the vagina; 

sheath-like. 
Vesalius, Andrew, a native of Brussels, 1514-64, was a pupil of Sylvius. He 

was the first author of a comprehensive view of human anatomy ; lias 

been called its founder. He fully described the sphenoid, sternum, and 

vestibule of the internal ear ; discovered and named the ductus venosus, 

and gave a full description of the brain. 
Ves'ical (accord, to L. quantity vesi'cal ; cf. cervi'cal, umbili'cal, vagi'nal) 

[vesVca, se, f., a bladder, especially urinary]. Relating to the bladder. 
Ver'umonta'num (L.) [veru, us, n., a spit, montanus, a, um, adj., mountain]. 

An elevation on the floor of the urethra. 



INDEX 



A. 

Acetabulum, 77, 79 
Admiuiculum, 140 
Agger nasi, 49 
Air-sinuses, 61 
Ala cinerea, 265 
Amphiarthrodial joints, 93, 94 
Angeiology, 19, 204 
Angle of pubis, 78 

sacro-vertebral, 23 

subcostal, 34 
Ankle-joint, 132 
Annulus inguinalis, 146, 119 
Antrum mastoideum, 41 

of Highniore, 48, 50 
Aorta, 208 
Aponeurosis, epicranial, 106 

intercostal, 156 

lumbar, 142 

of abdominal muscles, 147, 148 

of arm, 174 

of forearm, 176 

of leg, 194 

pharyngeal, 158 

vertebral, 142 
Aqueduct of cochlea, 43 

of Sylvius, 262 

of vestibule, 42 
Arch, crural, 149 

of aorta, 208 

palmar, 222 

plantar, 232 

subpubic, 80 
Arachnoid, 249, 252 
Area cribrosa, 42 

Artery or Arteries, anastomotica mag- 
na, 221, 229 

angular, 212 

aorta, 208 

abdominal, 223 
thoracic, 223 



Artery or Arteries, axillary, 219 
basilar, 218 
brachial, 220 
brachiocephalic, 209 
bronchial, 223 
carotid, 210, 214 
centralis retina, 216 
cerebellar, 217, 218 
cerebral, 216, 218 
cervical, 218 
choroid, 216, 218 
circumflex, 220, 230 

iliac, 229 
cceliac axis, 224 
colica, 225 
comes nervi ischiadic], 228 

phrenici, 219 
coronary, 212 
cremasteric, 229 
dental, 214 
dorsalis hallicis, 231 

indicis, 222 

pedis, 231 

pollicis, 222 
epigastric, 219, 228, 229 
facial, 211, 213 
femoral, 229 
gastric, 224 
gastro-duodenalis, 224 
gastro-epiploica, 224, 225 
gluteal, 226 
hemorrhoidal, 225, 257 
hepatic, 224 
iliac, 226, 228 
ileo-colic, 225 
ilio-lumbar, 226 
innominate, 209 
intercostal, 219, 223 
internal mammary, 219 

maxillary, 213 
interosseous, 222 
labial, 212 

361 



362 



INDEX. 



Artery or Arteries, laryngeal, 211, 228 
lingual, 211 
lumbar, 22 1 
mastoid, "J 1:3 
median, 222 
medullary, 20 

meningeal, 212, 213, 214, 217 
musculophrenic, 219 
nasal, 214, 216 
obturator, 227 
occipital, 212 
ophthalmic, 215 
orbital, 213 
ovarian, 226 
palatine, 212, 214 
pancreatico-duodeual, 224, 225 
perineal, 227 
peroneal, 232 
pharyngeal, 213 
phrenic, 224 
plantar, 232 
popliteal, 230 
princeps cervicis, 212 
. pollicis, 222 
profunda, 220, 230 

cervicis, 219 
pudic, 227, 229 
pyloric, 224 
radial, 221 
radialis indicis, 222 
ranine, 211 
receptaculi, 215 
renal, 225 
sacral, 224, 226 
scapular, 218, 220 
sciatic, 228 
sigmoid, 225 
spermatic, 226 
splenic, 224 

sterno-mastoid, 211, 212 
stylo-mastoid, 213 
subclavian, 216 
subscapular, 220 
superficialis volae, 221 
suprarenal, 225 
suprascapular, 218 
temporal, 213, 214 
thyroid, 211, 218 

axis, 228 
tibial, 231, 232 
tonsillar, 212 
tympanic, 213, 215 
ulnar, 222 
uterine, 227 



Artery or Arteries, vaginal, 2:27 

vertebral, 217 

Vidian, 214 
Arthrology, 19, 93 
Articulations, ilio-sacral, 121 

of costal cartilages and sternum, 101 

of lower extremity, 120 

of ribs and vertebra;, 99 

of trunk and head, 95 

of upper extremity, 104 

of vertebral column, 95 

temporo-maxillary, 103 
Asterion, 64 
Auricles, 205 
Auricular point, 64 

B. 

Basion, 64 

Bladder, 339 

Bone or Bones, analysis of, 22 

astragalus, 86 

atlas, 24 

axis, 25 

clavicle, 64 

cuboid, 88 

cuneiform, 73, 87, 88 

epihyal, 104 

epipteric, 56 

ethmoid, 47 

femur, 80 

fibula, 85 

frontal, 38 

humerus, 67 

hyoid, 35 

iliac, 77 

incus, 303 

innominate, 76 

intermaxillary, 50 

ischium, 78 

lachrj-mal, 53 

lunar, 73 

malar, 52 

malleus, 303 

maxillary, 48, 54 

metacarpal, 75 

metatarsal, 88 

nasal, 53 

navicular, 87 

number of, 22 

occipital, 35 

of Bertin, 45 

of carpus, 72 

of cranium, 35 



INDEX. 



363 



Bone or Bones of face, ->~\ I s 
of foot, 89 
of the head, 35 
of lower extremity, 76 

of palm, 75 

of tarsus, 86 

of trunk, 23 

of upper extremity, 64 

palate, 50 

parietal, 37 

patella, 83 

phalanges, 76, 89 

pisiform, 73 

pubic, 78 

pyramidal, 73 

radius, 71 

scaphoid, 73, 87 

scapula, 67 

semilunar, 73 

sesamoid, 78, 89 

sphenoid, 4-4 

spongy, 45, 48 

stapes, 303 

talus, 86 

temporal, 39 

tibia, 83 

trapezium, 73 

trapezoid, 74 

turbinate, 54 

ulna, 70 

unciform, 74 

vomer, 52 

Wormian, 56 
Brain, 252 
Bregma, 63 
Bronchi, 314 
Bursa?, carpal, 183 

intertubercularis, 109 

of elbow-joint, 111 

of hip-joint, 125 

of knee-joint, 127, 130 

of Monro, 106 

of shoulder-joint, 109 

prepatellar, 130 

pretibial, 128 

retro-epitrochlear, 1 12 

subacromial, 104 

subcrural, 127 

subpatellar, 128 

c. 

Calamus scriptorius, 265 

Calcar avis, 259 



Calcar femorale, 82 
Calvaria, 59 
Canal, crural, 187 

dental, 49, 53 

Hunter's, L92 

internal orbital, 57 

malar, 53 

medullary, 18 

neural, 18 

of Huguier, 40 

of nasal duct, 49 

orbital, 3rf 

palatine, 49, 51 

ptery go-palatine, 46, 51 

sacral, 29 

semicircular, 305 

spinal, 31 

temporal, 53 

vomero-basilar, 52 
Canaliculus innomiuatus, 47 
Cerebellum, 262 
Chiasma, 258, 266 
Chordae tendinese, 206 
Circle of Willis, 218 
Claustrum, 260 
Clitoris, 348 

Clivus Blumenbachii, 44 
Coccyx, 29 
Cochlea, 305 
Coelom, 18 
Colon, 328 
Concha, 301 
I Conchee sphenoidales, 45 
I Conus arteriosus, 206 
Cornea, 298 
Cornucopia, 265 
Corpus albicans, 258 

Arantii, 206 

callosum, 257, 259 

fimbriatum, 260 

quadrigeminum, 262 

striatum, 260 
Costal cartilages, 33 
Crest, frontal, 39 

incisor, 49 

infratemporal, 45 

lachrymal, 53 

nasal, 49 

obturator, 78 

occipital, 36 

of pubis, 78 

of tibia, 84 

sphenoidal, 45 

supramastoid, 39 



364 



INDEX. 



Crest, temporal, 38 

turbinate, 49, 51 
Crista falciformis, 42 

galli, 47 

orbitalis, 59 
Crus cerebri, 258 
Crystalline lens, 300 

D. 

Dartos, 145 
Deglutition, 164 
Development of ovum, 17 
Diaphragm, 152 
Diarthrodial joints 93, 94 
Duodenum, 325 
Dura mater, 249, 252 



E. 

Ear, 301 

Elbow-joint, 110 
Embryology, 17 
Eminence, deltoid, 68 

frontal, 38 

nasal, 38 

hypothenar, 184 

thenar, 184 

ilio-pectineal, 77 

olivary, 44 
Eminentia arcuata, 42 

articularis, 39 

capitata, 71 

cinerea, 265 

collateralis, 259, 260 

innominata, 36 
Epiblast, 17, 18 
Epididymis, 346 
Epiphysis, 20 

cerebri, 262 
Eustachian tube, 43, 302 

valve, 205 
Eye, 297 



Fallopian tubes, 351 
Fascia, 139 

anal, 150 

axillary, 154 

bucco-pharyngeal, 162 

Buck's, 149 

cervical, 157 

cremasteric, 148 



Fascia dentata, 260 

iliac, 148 

iufundibuliform, 148 

intercolumnar, 147 

lata, 186 

lumbar, 142 

masseteric, 171 

obturator, 150 

of abdomen, 145, 148 

of arm, 174 

of breast, 154 

of Colles, 149 

of forearm, 176 

of pelvis, 150 

of Scarpa, 145 

palmar, 183 

parotid, 158 

perineal, 149 

plantar, 198 

prevertebral, 158 

recto-vesical, 150 

semilunar, 175 

subpubic, 149 

temporal, 172 

transversalis, 148 
Fasciculus teres, 265 
Fat-pad, buccal, 171 
Fissure, calcarine, 256 

calloso-marginal, 256 

collateral, 257 

dentate, 256 

hippocampal, 256 

longitudinal, 257 

of Glaser, 40 

of Eolaudo, 255 

of Sylvius, 255 

parietal, 62 

parieto-occipital, 257 

petro-squamous, 40 

precentral,255 

pterygo-maxillary, 58 

sphenoidal, 46, 57 

spheno-maxillarv. 57 
Flocculus. 263 
Fontanelle, 62 
Foramen, aortic, 153 

csecum, 39 

carotico-clinoid, 47 

carotico-tympanicus, 4! 

centrale cochlea', 42 

condylar, 36 

inferior dental, 55 

infraorbital, 48, 49 

intervertebral, 24, 30 



INDEX. 



365 



Foramen, Jaeobson's, 43 
jugular. :>7 
Iacerum, 59 

mastoid, 40 

mental, 54 

obturator, 77, 7!) 

of Magendie, 2.~>:> 

of Monro, 259, 261 

of Vesalius, 47 

optic, 44, 46, 57 

ovale, 46 

parietal, 37 

quadratum, 153 

rotundum, 45, 46 

sacral, 23 

singulare, 42 

spiuosum, 46 

sternal, 32 

stylo-mastoid, 43 

supratrochlear, 69 

thyroid, 77, 79 
Foramina, incisor, 49 

of Scarpa, 49 

of Stenson,49 

Thebesii, 205 
Fornix, 261 
Fossa acetabuli, 79 

anterior palatine, 49, 53 

canine, 48 

condylar, 36 

coronoid, 69 

digastric, 40 

digital, 81 

glenoid, 40, 67 

guttural, 58 

hypo-trochauterica, 83 

iliac, 77 

incisor, 48, 54 

infraspinous, 66 

infratemporal, 58 

intercondylar, 82 

jugular, 43 

lachrymal, 38, 57 

mandibularis, 40 

myrtiform, 48 

nasal, 60, 308 

olecranon, 69 

ovalis, 205 

pituitary, 44 

pterygoid, 46 

radial, 69 

scaphoid, 46 

sigmoidea, 41 

spheno-maxillary, 58 



Fossa, snbarcuate, 42 

subscapular, 65 

supraspinous, 66 

temporal, 57 

trochlear, 38 

zygomatic, 58 
Funiculus of Rolando, 253 

cuneatus, 253 

gracilis, 253 

G. 

Galea aponeurotica, 166 
Gall-bladder, 333 
Ganglion, cervical, 292, 293 

Gasseriau, 267 

geniculate, 272 

jugular, 274 

Meckel's, 269 

ophtbalmic, 268 

otic, 271 

petrous, 274 

semilunar, 295 

submaxillary, 271 
Geniculate bodies, 262 
Gerdy's fibres, 183 
Glabella, 38 
Gland, mammary, 352 

parotid, 321 

prostate, 342 

sublingual, 321 

submaxillary, 321 

thymus, 315 

thyroid, 315 
Groove, basilar, 37 

bicipital, 68 

infraorbital, 49 

lachrymal, 49 

mylo-hyoid, 55 

obturator, 78 

olfactory, 48 

optic, 44 

posterior palatine, 51 

spiral, 68 

subcostal, 33 
Gyrus, angular, 256 

fornicatus, 257 

hippocampi, 257 

marginal, 256 

opertus, 256 

uncinate, 257 



H. 



Heart, 204 



36G 



INDEX. 



Hemiarthrosis, 94 
Henle's ankle-joint, 133 
classification of joints, 94 
vertebral ligaments, 100 
wrist-joint, 1 1 1 
1 lip-joint, 123 
Hippocampus, 259, 260 
Homologies, muscular, 202 
of carpus and tarsus, 92 
of ilium and scapula, 92 
of upper and lower limbs, 91 
Hypoblast, 17, 18 
Hypophysis cerebri, 258 



Ilio-tibial band, 186 
Index, huniero-radial, 72 

of cranium, 64 

sacral, 29 
Infundibulum, 47, 258, 306 
Inion, 64 

Intervertebral disks, 96 
Intestines, 324 
Iris, 299 
Island of Reil, 256 

J. 

Joints, classification of, 93 



Kidney, 336 
Knee-joint, 125 



K. 



L. 



Labyrinth, 47, 305, 306 
Lacertus fibrosus, 175 
Lambda, 63 
Lamina cinerea, 257 
cribrosa, 42 
papyracea, 47 
Larrey's space, 153 
Larynx, 310 
Ligament or Ligaments, accessory, 95 

of astragalus, 135 

of forearm, 113 

of hip, 154 

of knee, 128 

of tarsus, 136 

of wrist, 116 

tibiofibular, 134 



Ligament or Ligaments, accessorium 
laterale, 103, 129 

mediale, 103, 129 

radiale, 119 

ulnare, 119 
acromioclavicular, 106 
alar, 99, 127 
annular, 116, 194 
anterior, 95, 110, 114, 128, 132 
arcuate, 118, 121, 128, 153 
astragalo-scaphoid, 133 
atlo-axoid, 98 
Bertini, 124 
brachial, 174 
calcaneo-astragaloid, 133 
calcaneocuboid, 133, 136 
calcaneo-fibulare, 136 
calcaneo-naviculare, 136, 137 
calcaneo scaphoid, 133, 136 
calcaneo-tibiale, 136 
capituli fibula, 131, 132 
capitulorum, 138 

dorsal ia, 120 

volaria, 119 
capsular of elbow, 110 

of hip, 123 

of knee, 127 

of lower jaw, 103 

of shoulder, 107 

of vertebra?, 96 

of wrist, 115 
carpi commune, 116 

dorsale profundum, 117 

volare profundum, 118 
proprium, 117 
carpo-metacarpea, 1 17 
chondro-sternal, 101 
chondro-xiphoid, 102 
colli costee, 101 
conjugal, 100 
conoid, 107 
coraco-acromial, 104 
coraco-clavicular, 107 
coraco-glenoidale, 109 
coraco-humeral, 109 
coronary, 126 
corruscans, 102 
costoclavicular, 106 
costo-coracoid, 154 
costo-transverse, 100, 101 
costo- vertebral, 99, 100 
cotyloid, 123 
crucial, 98, 126, 194 
cuboideo-naviculare, 137 



INDEX. 



367 



Ligament or Ligaments, cuneo-cu- 
boidea, 136 

deltoid, 132 
denticalatum, 21!> 

dorsal. 111. 119, 120, 133 
falciform, 122 
Flood's, 109 

fundiform of Retzius, 194 
Gimbernat's, 117 

reflected, 147 
glenoid, 108 
glenoideo-brachial, 109 
glenoideo-humeral, 109 
hamo-metacarpeum, 119 
humero-coronoid, 111 
humero-olecranon. Ill 
iliacum proprium, 120 
ilio-femoral, 121 
ilio-lurnbar, 121 
ilio-pectineal, 149 
ilio-troehanteric, 124 
inguinal, 147, 149 
interarticular, 100 

fibro-cartilage, 103, 106 
intercarpea, li? 
interchondral, 102 
interclavicular, 106 
intercostal, 102 
intercruralia, 101 
intermetacarpea, 117, 119 
interraetatarsea, 136. 137 
interrauscularia, 174 
interosseous, 113, 111, 132, 133 
interspinous, 96 
intersternal, 102 
intertransverse, 97 
intrajugular, 103 
ischio-capsular, 124 
ischio-femoral, 124 
laciniatum, 194 

lateral, 99, 103, 111, 113, 129, 132 
latum. 99 
lumbo-costal, 101 
malleoli lateralis, 134 
metatarsal, 133 
metatarso-phalangeal, 138. 
mucosum, 115, 127. 179 
naviculari cuboidea, 136 
nucha?, 96 
oblique. 113, 128 
obturator, 98, 120 
occipito-atloid, 98, 99 
occipito-axoid, 99 
odontoid, 99 



Ligament or Ligaments of ankle- 
joint, 132 
of Barkow, 111 
of Bigelow, 124 

Of bladder. 150 

of Burns, 187 

of carpus, 11 1 

of ilio-sacral joint, 121 

of Colles, 147 

of elbow-joint, 110 

of Hey, 187 

of hip-joint, 123 

of knee-joint, 125 

of larynx, 311 

of metacarpus, 114 

of phalanges, 114, 133 

of rectum, 150 

of scapula, 104 

of shoulder-joint, 107 

of skull, 102 

of tarsus, 132, 136 

of uterus, 351 

of Winslow, 128 

of wrist-joint, 113 

of Ziun, 170 

olecrano-coronoid, 111 

orbicular, 111, 124 

palmar, 114 
palpebral, 167 
patellae, 128 

petro-sphenoidal, 43, 103 
piso-hamatum, 119 
piso-nietacarpeurn, 119 
plantar, 133 

plica? synov. patellaris, 127 
popliteum arcuatum, 128 
posterior, 95. Ill, 114, 128, 132 
Poupart's, 146 
pterygo-maxillary, 104 
pterygo-petrosal, 103 
pubo-fenioral, 124 
pubo-prostatic, 150 
radiate, 118 
radio-ulnar, 113 
retinacula tendinum, 120 
retinaculum, 109 
lig. arcuati, 128 
peronseorum, 194, 196 
sacro-coccygeum articulare, 97 
sacro-sciatic, 122 
sacro-spinosum, 122 
sacro-tuberosum, 122 
scapho-cuboid, 133 
scapulo-claviculai-, 107 



368 



INDEX. 



Ligament or ■ Ligaments, Schlemm's, 
109 

semilunar fibro-cartilages, 126 

sphenomaxillary, 104 

spiuo-glenoid, 105 

stellate, 99 

sterno-clavicular, 105 

stylo-hyoid, 104 

stylo-maxillary, 103 

stvlo-inyloid, 103 

subflava, 96, 179 

subpubic, 121 

suprascapular, 105 

supraspinous, 96 

suspensoiy of eye, 171 
of penis, 145 

talo-calcanea, 135 

talo-cruralia, 135 

talo-fibulare, 135 

talo-naviculare, 136 

talo-tibiale, 135 

tarseum trausversum, 137 

tarso-metatarsea, 136 

teres, 123 

tibio-calcaneo-naviculare, 135 

tibio-fibular, 131, 134 

tibio-naviculare, 136 

transverse, 98, 105, 114, 119, 123, 
128, 132, 183 
humeral, 109 
of pelvis, 150 

trapezoid, 107 

triangular 147, 149 
fibro-cartilage, 113 

tuberculi costse, 101 

tuberositatum vertebralium, 101 

vaginalia, 119, 120, 179 

vincula tendinum, 179 
Ligula, 265 

Lingual convolution, 257 
Lingula, 263 

mandibular, 55 

sphenoidal is, 44 
Limbus sphenoidalis, 44 
Line, buccal, 55 

gluteal, 77 

ilio-pectineal, 77 

intertrochanteric, 81 

oblique, 54, 71, 84, 85 

popliteal, 84 

spiral, 81 

temporal, 37 
Linea alba, 146 

aspera, 81 



Linea Douglasii, 147 

quad rati, 81 

semilunaris, 146 

Spigelii, 148 

splendens, 249 

transversa, 146 
Liver, 331 
Lobe, central, 256 

frontal, 255 

occipital, 256 

parietal, 255 

temporo-sphenoidal, 27)6 
Locus niger, 259 
Lungs, 316 
Lymphatic glands, axillary, 248 

cervical, 248 

inguinal, 245 

mesenteric, 246 

pelvic, 246 

thoracic, 247 
Lymphatics of lower limb, 245 

of abdomen, 246 

of head and neck, 248 

of pelvis, 246 

of thorax, 247 

of upper limb, 247 

M. 

Malleolus, 84 

Mandible, 54 

Marrow, 21 

Meatus of nose, 48, 61 

Mediastinum, 316 

Medulla oblongata, 253 

Membrana sacciformis, 113 

tympani, 302 
Meniscus, 126 
Mesoblast, 17, 18 
Midriff; 152 
Modiolus, 305 
Mouth, 318 

Muscle or Muscles, abductor hallicis. 
199 
indicis, 185 
minimi dig., 184, 200 
ossis metatarsi quinti, 200 
pollicis, 182, 184 
accessorius, 179 
acromio-clavicularis, 173 
adductor brevis, 193 
gracilis, 193 
hallicis, 200 
longus, 193 



iNDi:.\. 



369 



Muscle or Muscles, magnus, 193 
minimus, li>3 
pollicis, 184 

agitator caudse, 188 
amygdalo-glossus, 163 
anconeus, 1?(!, 181 

quintus, 176 
epitrochlearis, 176' 
anomalus, 1(59 
menti, 170 

articularis genu, 191 
aryteno-epiglottie, 313 
arytenoideus, 31 1 
atlanto-mastoideus, 145 
auricularis, 166, 167 
azygos pharyngis, 163 

u vuhe, 163 
biceps, 174 

feuioris, 192 
biveuter cervicis. 143 

mandibular, 158 
bracbialis auticus, 175 

interims, 175 
brachio-radialis, 180 
buccinator, 169 
bulbo-cavernosus, 152 
eaninus, 168 

cephalo-pharyugeus, 162 
cervico-costo-humeralis, 160 
chondro-epitrochlearis, 154 
chondroglossus, 161 
ciliary, 299 
circuniflexus, 163 
cleido-hyoideus, 159 
cleido-occipital, 153 
coccygeus, 151 
coniplexus, 143 
compressor hemisph. bulbi, 152 

naris, 169 

urethras, 152 

vena; dorsalis penis, 152 
constrictor of pharynx, 162 
coraco-brachialis, 175 
coraco-capsularis, 175 
coraco minor, 175 
corrugator supercilii, 167 
costo-coracoid, 141 
costo-fascialis, 160 
cremaster, 148 
crico-arytenoideus, 314 
crico-hyoideus, 160 
crico-thyroid, 313 
crureus, 191 
cubito-carpeus, 179 

24 — Anat. 



Muscle or Muscles, curvator cocevgi- 
151 
deltoid, 17:5 
depressor alse nasi, 169 
anguli oris, 168 
labii inferioris, 169 
septi, 169 
diaphragm, 152 
digastric, 159 
dilator naris, 169 
dorso-epitrochlearis, 141, 176 
ejaculator urinse, 152 
epicranius, 166 

temporalis, 166 
erector penis, 151 

spinas, 142 
extensor brevis digit, 198 
digit, ruanus, 182 
pollicis, 182 
carpi rad. access., 180 
brevior, 180 
coccygis, 143 
intermedins, 180 
longior, 180 
ulnaris, 181 
communis digit., 180 
digiti quinti, 181 
hallicis brevis, 199 
indicis proprius, 182 
longus hallicis, 195 
digit., 195 

primi internodii hall., 195 
pollicis, 182 
medii digiti, 182 
minimi digiti, 181 
ossis metac. poll., 182 
primi internod. poll., 182 
sec. intern, poll., 182 
flexor brevis digit., 199 
accessorius, 199 
hall., 200 
min. dig., 184, 200 
poll., 184 
carpi radialis, 177 
brevis, 170 
ulnaris, 17/ 
brevis, 179 
longus digitorum, 197 
access., 197 
hall., 198 
pollicis, 179 
sublimis digit., 178 
profundus digit., 178 
frontalis, 166 



370 



INDEX. 



Muscle or Muscles, gastrocnemius, 
196 

gemelli, 189 
genio-hyoglossus, 161 
genio-hyoideus, 160 
glosso-staphyliuus, 163 
glutei, 188 
gluteo-perinealis, 151 
gracilis, 171, 193 
Horner's, 167 
hyoglossus, 161 
hyo-pharyngeus, 162 
hyo-thyroideus, 160 
iliacus, 187 

miuor, 188 
ilio-costalis cervicis, 143 

dorsi, 143 

lumboruru, 143 
ilio-psoas, 187 
incisivi, 169 
indicator, 182 
infraspinatus, 173 
interclavicular, 154 
intercostales, 156 
interossei, 185, 200 
interspinales, 144 
intertransversales, 144 
intertransversarii, 165 
ischio-aponeuroticus, 193 
ischio-cavernosus, 151, 152 
ischio-coccygeus, 151 
labii proprius, 169 
laryngo-pharyngeus, 162 
latissimus dorsi, 140 

anguli oris, 168 

labii sup., 168 
levator ani, 151 

claviculse, 158 

menti, 170 

palati, 163 

palpebrse, 170 

scapulae, 165 
levatores costaruni, 144 
lingualis, 161 
longissimus capitis, 143 

cervicis, 143 

dorsi, 143 
lougus atlautis, 165 

capitis, 165 

colli, 165 
lumbricales, 183, 199 
malaris, 1H7 
masseter, 171 
mental is, 170 



Muscle or Muscles, mento-hyoid, 158 
multifidus, 144 
myloglossus, 161 
mylohyoideus, 160 
nasalis, 169 
naso-labialis, 169 
oblique, inferior, 170 

superior, 170 
obliquus capitis, 144 

externus, 146 

interims, 147 
obturator, 189 
occipitalis, 166 

minor, 157 
occipito-frontalis, 166 
occipito-pharyngeus, 163 
occipito-scapularis, 140 
of abdomen, 145 
of arm, 174 
of back, 139 
of breast, 154 
of foot, 198 
of forearm, 176 
of hand, 183 
of head, 166 
of hip, 187 
of hyoid bone, 158 
of leg, 195 
of neck, 157 
of orbit, 170 
of palate, 163 
of perineum, 150 
of pharynx, 162 
of scapula, 173 
of thigh, 190 
of tongue, 161 
of trunk, 139 
omo-hyoideus, 159 
opponens hallicis, 200 

minimi dig., 185, 200 

pollicis, 184 
orbicularis oculi, 167 

oris, 169 
palato-glossus, 163 
palato-pharyngeus, 163 
palato-staphylinus, 163 
palmaris brevis, 183 

lougus, 177 
papillares, 206 
pectinati, 205 
pectineus, 193 
pectoralis major, 154 

minor. 155 

minimus. 155 



INDEX. 



371 



Muscle or Muscles, peroneo-calcaneus, 
198 
peroneo-tibialis, 197 
peroneus access., 19b' 

brevis, 196 

longus, 195 

quartus, 19(5 

quint, digiti, 196 

tertius, 195 
petro-pharyngeus, 1<>3 
petro-staphylinus, 163 
pharyngo-mastoideus, 163 
pharyngo-staphylinus, 163 
pisi-annularis, 185 
pisi-nietacarpeus, 185 
pisi-uncinatus, 185 
plantaris, 197 
platysma rnyoides, 157 
popliteus, 197 

minor, 197 
pronator quadratus, 179 

teres, 177 
psoas magnus, 188 

parvus, 188 
pterygoideus, 172 

proprius, 172 
pterygo-pharyngeus, 163 
pterygo-spinosus, 172 
pubo-coccygeus, 151 
pubo-transversalis, 148 
pyramidalis, 146 

nasi, 169 
pyriformis, 189 
quadratus femoris, 189 

labii sup., 168 

lumborurn, 187 

menti, 169 

plantar, 199 
quadriceps femoris, 190 
radialis internus, 177 
radio-carpeus, 179 
recti of eye, 170 
rectus abdominis, 145 

capitis anticus, 165 
lateralis, 145 
posticus, 144 

femoris, 191 

lateralis abd., 146 
rbombo-atloideus, 141 
rhomboid eus major, 140 

minor, 140 

occipitalis, 140 
risorius, 168 
rotatores, 144 



Muscle or Musdles, sacro-coccygeus, 
1 13, 151 
sacro-lumbalis, 142 
sacro-spinalis, L42 
sartorius, 190 
scaleni, 164 
scalenus minimus, 165 

pleural is, 165 
semimembranosus, 192 
semispinals, 143 
semitendinosus, 192 
serratus anticus, 155 

magnus, 155 

posticus, 141 
soleus, 196 

spheno-pbaryngeus, 163 
spheno-staphylinus, 163 
sphincter ani, 151 

oris, 169 
spinales, 143 
splenius, 141 

capitis access., 141 

colli access., 141 
stapedius, 304 
sternalis brutorum, 154 
sterno-clavicularis, 154 
sterno-cleido-mastoid, 158 
sterno-hyoideus, 159 
sterno-scapularis, 154 
sterno-thyreoideus, 160 
stylo-auricularis, 161 
stylo-glossus, 161 
stylo-hyoideus, 159 

alter, 159 

profundus, 159 
stylo-pharyngeus, 162 
subanconeus, 176 
subclavius, 154 
subcruralis, 191 
subcutaneus colli, 157 
subdeltoid, 173 
subscapulars, 174 

minor, 174 
supinator brevis, 182 

longus, 180 
access., 180 
supraclaviculars, 154 

proprius, 158 
supracostalis, 156 
supraspinatus, 173 
temporal, 172 

minor, 172 
tensor palati, 163 

tarsi, 167 



:*72 



INDEX. 



Muscle or Muscles, tensor trochlea, 
171 

t \ mpani, 304 

vaginae fenioris, 190 
teres major, 140 

minor, 173 
thyreo-hyoideus, 160 
thyro arytenoid, 313 
thyro-epiglottic, 313 
tibialis antieus, 194 

posticus, 197 

secundus, 197 
tibio-fascialis, 195 
trachelo-mastoid, 143 
transversalis abd., 148 

cervicis, 143, 165 
transversi thoracis, 156 
transverso-spinalis, 143 
transversus colli, 160 

menti, 168 

n ncbse, 158 

orbitse, 171 

pedis, 200 

perinei, 151 
profundus, 152 
trapezius, 139 
triangularis menti, 168 

stern i, 156 
triceps, 175 

surse, 196 
triticeo-glossus, 161 
trochlearis, 170 
ulnaris extern us, 181 

internus, 177 

brevis, 179 

quinti digiti, 181 
ulno-carpeus, 179 
vasti, 191 
zvgomaticus, 168 
Myology, 19, 138 

N. 
Nasi on, 63 
Nerve or Nerves, ahducens, 271 

anterior crural, 286 

Arnold's, 275 

auditory, 273 

auricularis magnus, 279 

auriculo-temporal, 270 

cardiac, 276, 293 

chorda tympani, 272. 304 

ciliary, 268 

circumflex, 281 



Nerve or Nerves, communicans mini, 
279 
cranial, 266 
descendens ooni, 277 
dorsal, 283 
facial, 272 
genito-crural, 285 
glosso-pharyngeal, 273 
gluteal, 288 
gustatory, 271 
hypoglossal, 277 
ilio-hypogastric, 285 
ilioinguinal, 285 
inferior maxillary, 270 
infraorbital, 269 
interosseous, 282, 283 
Jacobson's, 274, 304 
laryngeal, 275 
lingual, 271,274 
lumbar, 283 
median, 281 
motor oculi, 267 
musculocutaneous, 281, 291 
musculo-spiral, 283 
nasal, 268, 269 
obturator, 286 
occipitalis minor, 279 
olfactory, 266 
ophthalmic, 267 
optic, 266 
orbital, 269 
pathetic, 267 
perineal, 289 
peroneal, 291 
petrosal, 270, 272, 274 
pharyngeal, 270, 275 
phrenic, 279 
plantar, 290 
pneumogastric, 274 
popliteal, 289, 291 
pudic, 289 
radial, 283 
saphenous, 287 
sciatic, 288, 289 
spinal accessory, 276 
splanchnic, 294 
suboccipital, 277 
superficialis colli, 279 
superior maxillary, 269 
suprascapular, 280 
sympathetic, 292 
thoracic, 280 
tibial, 290, 291 
trifacial, 267 



[NDEX. 



373 



Nerve or Nerves, tympanic, 272, 274 

ulnar. 282 

Vidian, 270 
Neural arch, 24 
Neuroglia, 251 
Neurology, 19, 249 
Nose, 307 
Notch, coraco-scapular, 67 

cotyloid, 79 

episternal, 32 

ethmoidal, 38 

great scapular, 66 

iliac, 77 

ilio-sciatic, 78 

intercondylar, 82 

jugular, 37 

lachrymal, 49 

nasal 38, 48 

parietal, 40 

popliteal, 84 

pterygoid, 48 

sciatic, 77, 79, 122 

semilunar, 32, 55 

sigmoid, 55 

spheno-palatine, 52 

suprascapular, 67 

vertebral, 24 
Notochord, 17 
Nucleus amygdala?, 260 

caudate, 260 

lenticular, 260 

o. 

Obeli on, 63 
Obex, 265 
Occipital point, 63 
Oesophagus, 322 
Olecranon, 70 
Olfactory tract, 258 
Olivary body, 253 
Omentum, 341 
Operculum, 256 
Ophryon, 63 
Opisthion, 64 
Optic commissure, 258, 266 

thalamus, 261 

tract, 258, 266 
Orbital plate, 38, 45, 47 
Orbits, 57 
Organ of Corti, 307 
Os acetabuli, 79 

capitatum, 74 

centrale, 75 



Os coxa', 7<» 
innominatum, 76 
planum, 17 

pubis, 78 

trigonum, 88 
Ossa supersternalia, 32 

triquetra, 56 
Ossiculum jugulare, 56 
Ossification, 20 
Osteology, 19 
Ovary, 351 

P. 

Palate, 320 
Palatine trigone, 49 
Pancreas, 324 
Panniculus adiposus, 139 

carnosus, 139 
Parietal boss, 37 
Parovarium, 352 
Pars intermedia, 272 
Patella, 83 

Peduncles of cerebellum, 263 
Pelvic girdle, 91, 120 
Pelvis, 76, 79 

position of, 80 

differences in, 80 
Penis, 342 
Pericardium, 204 
Perimysium, 138 
Periosteum, 20 
Peritoneum, 339 
Pes accessorius, 259, 260 

hippocampi, 260 
Phalanges, 76, 89 
Pharynx, 322 
Pia mater, 249, 252 
Pillar of fauces, 163 
Pineal gland, 262 
Pituitary body, 258 
Pleura, 315 
Plexus, brachial, 280 

cardiac, 294 

carotid, 292 

cavernous, 292 

cervical, 278 

epigastric, 295 

lumbar, 284 

pelvic, 296 

sacral, 288 
Pons Varolii, 254 
Porus acusticus, 42 
Posterior nares, 59 



374 



INDEX. 



Precuneus, -J.")? 
Primitive streak, 17, 18 
Process, accessory, -J? 

alveolar, 49 

angular, 38 

articular, 24, .'31 

clinoid, 44, 45 

cochleariform, 43 

coracoid, <><> 

coronoid, 55, 70 

ensiform, 32 

ethmoidal, 54 

frontal, 52 

hamular, 4G, 54 

incisor, 50 

intrajugular, 37 

jugular, 36 

lachrymal, 54 

malar, 49 

mammillary, 27 

marginal, 53 

mastoid, 40 

maxillary, 51, 54 

nasal, 38, 49 

odontoid, 25 

orbital, 51, 53 

palate, 49 

paraxnastoid, 37 

petrosal, 44 

pyramidal, 51 

sphenoidal, 51 

spinous, 24, 30, 45 

styloid, 43, 71, 72, 75, 85 

superior turbinate, 48 

supracondylar, 69 

transverse, 24, 30 

tubarius, 46 

uncinate, 47, 74 

ungual, 76 

vaginal, 43, 44, 46 

xiphoid, 32 
Processes of Ingrassias, 45 

pterygoid, 44, 46 
Pyramid, 253 

R. 

Radio-carpal joint, 115 
Radius, 71 

Receptaculum chvli, 245 
Rectum, 329 
Restiform bodv, 253 
Retina, 299 
Ribs, vertebro-sternal, 32 



Ribs, vertebro-chondral, 32 

vertebral, 32 
Ridge, gluteal, M 

mylo-hyoid, 55 

pectoral, 68 

pronator, 71 

superciliary. 38 

supinator, 68, 70 

supracondylar, 68, 81 
Ring, abdominal, 146, 149 

(rural, 187 

femoral, 149 
Rostrum, 45, 259 

s. 

Saccus endolymphaticus, 42 
Sacrum, 28 
Sagittal plane, 19 
Saphenous opening, 187 
Sarcolemma, 138 
Scapula, 65 
Scarpa's triangle, 229 
Sclerotic coat, 298 
Scrotum, 345 
Segmentation sphere, 17 
Sella turcica, 44 
Semilunar'valves, 206 
Septum cruralc, 187 

lucidum, 259, 261 

nasi, 60 

tubas, 43 
Sesamoid plate, 138 
Sheath, crural, 187 

of rectus, 147 
Shoulder, 64 
Shoulder-girdle, 90, 104 
Shoulder-joint, 107 
Sigmoid cavity, 70, 72 
Sinus, cavernous, 238, 271 

circular, 238 

coronarv, 233 

frontal ,*38 

lateral, 238 

longitudinal, 238 

magnus, 209 

maxillary, 50 

occipital, 238 

petrosal, 238 

straight, 238 

transverse, 239 
Skeleton, 19 
Skull, as a whole. 55 

fixed points on, 63 



NDEX. 



375 



Somatopleuit . 18 
Spermatic cord. 344 

Sphenoethmoidal recess, 61 
Sphono-petrosal lamina, 47 
Spinal cord, 249 
Spine, 44 

iliac, 79 

nasal, 48, 51 

of ischium, 77 

of pubis, 77 

of scapula, (>6 

of tibia, 84 

palatine, 51 

peroneal, 86 
Spines, mental, 54 
Splanchnology, 19, 310 
Splanchnopleure, 18 
Spleen, 335 
Splenium, 259 
Stapes, 303 
Stephanion, 64 
Sternum, 31 
Stomach, 323 
Stria? acoustics, 265 
Subnasal point, 63 
Substantia ferruginea, 266 

gelatinosa, 251 
Sulci of brain, 255 
Sulcus, frontal, 39 

occipitalis, 41 

preauricular, 79 

pulmonalis, 34 
Superior maxilla, 48 
Supination, 112, 131 
Suprarenal capsule, 335 
Sustentaculum tali, 86 
Sutures, coronal, 56 

lambdoid, 56 

sagittal, 56 
Symphysis pubis, 78, 120 
Synarthrodia! joints, 93 
Synchondrosis, 94 
Syndesmosis, 94 
Synovial cavities of ankle, 137 
of wrist, 116 

membrane, 93 

T. 

Tsenia scmicircularis, 260 

Talus, 86 

Tarsus, 86 

Teeth, 318 

Tegmen tyinpaui, 40, 42 



Tegmentum, 259 
Tendo Achillis, 19? 

oculi, 167 
Tentorium, 252 

Testis, 344 

Thigh, 80 

Thorax, 31, 34 

Tibia, 83 

Tongue, 309 

Tonsil, 263, 320 

Torcular Herophili, 36 

Torus occipitalis transversus, 37 

Trachea, 314 

Tractus spiralis foramiuulentus, 42 

Tragus, 301 

Trapezium, 254 

Triangle of Petit, 147 

suboccipital, 145 
Trochanters, 81 
Trochlea, 69 
Tuber annulare, 254 

cinereum, 258 

olfactorium, 258 
Tubercle, adductor, 82 

carotid, 26 

Chassaignac's, 26 

conoid, 65 

deltoid, 65 

infraglenoid, 67 

lachrymal, 49 

Lisfranc's 33 

mental, 54 

obturator, 78 

of femur, 81 

of radius, 72 

of the quadratus, 81 

of tibia, 84 

pharyngeal, 37 

pterygoid, 46 

scalene, 33 

supraglenoid, 67 
Tubercles of astragalus, 87 
Tuberosity, bicipital, 71 

costal, 65 

great, 68 

iliac, 77 

of ischium, 78, 79 

of scaphoid, 73, 87 
small, 68 

of superior maxilla, 48 

of the palate-bone, 51 

of tibia, 83 

of trapezium, 74 

of ulna, 70 



37G 



INDEX. 



Tuberosity, pubo-ischiatic, 78 
Tympanic plate. 44 
Tynipanuiii, 301 



u. 



Ulua, 70 
Ureter, 337 
Urethra, 343, 349 
Uterus, 349 



Vagina, 349 

Valve of Vieussens, 263, 265 

Vas deferens, 347 

Vein or Veins, angular, 235 

axillary, 240 

azygos, 240, 241 

basilic, 240 

cardiac, 233 

cava inferior, 241 
superior, 233 

cephalic, 240 

cerebellar, 237 

cerebral, 237 

cervical, 234 

coronary, 233 

corporis striati, 237 

diploic, 239 

emissary, 239 

facial, 235 

femoral, 243 

hepatic, 242 

iliac, 242, 243 

innominate, 234 

intercostal, 235 

internal maxillary, 236 

jugular, 236, 237 

lumbar, 241 

magna Galeui, 237 

median, 240 

oblique of Marshall, 233 

ophthalmic, 239 



Vein or VeinS, popliteal, 243 

porta', 244 

pudic, 243 

pulmonary, 233 

renal, 242 

saphenous, 242 

spermatic, 242 

spinal, 241 

subclavian, 240 

systemic, 233 

temporal, 236 

temporo-maxillaiy, 235 

thyroid, 234 

tibial, 243 

ulnar, 240 

vertebral, 234 
Velum interpositum, 261 

medullary, 263, 265 

palati, 163 
Ventricles, 205 

of brain, 259, 262, 263 
Vertebra dentata, 25 

prominens, 25 
Vertebrae, cervical, 24 

characteristics of, 23 

dorsal, 26 

false, 28 

lumbar, 26, 27 

sacral, 28 
Vertebral, 25 

column, 23, 29 
Vestibule, 305 
Vincula tendinum, 179 
Vitelline membrane, 17 
Vocal cords, 312 
Vulva, 348 

w. 

"White line," 150 
Wings of sphenoid, 44, 45 
Wrist-bones, 72 
Wrist-joint, 113 



LEA BROTHERS & CO'S LIST 

OF THE 

Leading Medical Text-Books 



Anatomy, Dictionaries. 
Gray's Anatomy— 12th Edition. Colors or Black. 

Anatomy, Descriptive and Surgical. By Henry Gray, 
F. R. S., Lecturer on Anatomy at St. George's Hospital, London. Edited 
by T. Pickering Pick, F. R. C.S., Surgeon to and Lecturer on Anatomy 
at St. George's Hospital, London, Examiner in Anatomy, Royal College of 
Surgeons of England. A new American from the eleventh enlarged and 
improved London edition, thoroughly revised and re-edited by William 
W. Keen, M. D., Professor of Surgery in the Jefferson Medical College of 
Philadelphia. To which is added the second American from the latest 
English edition of Landmarks, Medical and Surgical, by Luther 
Holden, F. R. C. S. In one imperial octavo volume of 1098 pages, with 
685 large and elaborate engravings on wood. Price of edition in black : 
Cloth, $6.00 ; leather, $7.00 ; half Russia, $7.50. Price of edition in colors : 
Cloth, $7.25 ; leather, $8.25 ; half Russia, $8.75. 

As the book now goes to the purchaser he is 
receiving the best work on anatomy that is 
published in any language. — Virginia Medi- 
cal Monthly, December, 1887. 

Gray's standard Anatomy has been and will 
be for years the text-book for students. The 
book needs only to be examined to be per- 
fectly understood. — Medical Press of Western 
New York, January, 1888. 



The most popular work on anatomy ever 
written. It is sufficient to say of it that this 
edition, thanks to its American editor, sur- 
passes all othereditions.— Journal of the Amer- 
ican Medical Association, December 31, 1887. 

Gray's Anatomy is the most magnificent 
work upon anatomy which has ever been pub- 
lished in the English or any other language. 
— Cincinnati Medical News, Nov. 1887. 



Dunglison's Medical Dictionary. 

MEDICAL LEXICON; A Dictionary of Medical 
Science : Containing a concise Explanation of the various Subjects and 
Terms of Anatomy, Physiology, Pathology, Hygiene, Therapeutics, Phar- 
macology, Pharmacy, Surgery, Obstetrics, Medical Jurisprudence and 
Dentistry, Notices of Climate and of Mineral "Waters, Formulae for Officinal, 
Empirical and Dietetic Preparations. With the Accentuation and Ety- 
mology of the Terms, and the French and other Synonymes, so as to 
constitute a French as well as an English Medical Lexicon. By Robley 
Dunglison, M. D., Late Professor of Institutes of Medicine in the Jeffer- 
son Medical College of Philadelphia. Edited by Richard J. Dunglison, 
M. D. In one very large and handsome royal octavo volume of 1139 pages. 
Cloth, $6.50; leather, raised bands, $7.50; very handsome half Russia, 
raised bands, $8.00. 



Dictionaries, Physiology. 
Hoblyn's Medical Dictionary. 

A Dictionary of the Terms Used in Medicine and 
the Collateral Sciences. By Richard D. Hoblyn, M. D. Revised, 
with numerous additions, by Isaac Hays, M. D., late editor of The Amer- 
ican Journal of the Medical Sciences. In one large royal 12mo. volume of 
520 double-columned pages. Cloth, $1.50 ; leather, $2.00. 

It is the best book of definitions we have, and ought alwuys be upon the student's table. 
— Southern Medical and Surgical Journal. 



Foster's Physiology— New (Fifth) Edition. 

Text-Book of Physiology. By Michael Foster, M. D., 
F.R. S., Prelector in Physiology and Fellow of Trinity College, Cambridge, 
England. New (fifth) and enlarged American from the fifth and revised 
English edition, with notes and additions. In one handsome octavo vol- 
ume of 1072 pages, with 282 illustrations. Cloth, $4.50 ; leather, $5.50. 

editions has been by the author largely 



The appearance of another edition of 
Foster's Physiology again reminds us of the 
continued popularity of this most excellent 
work. There can be no doubt that this text- 
book not only continues to lead all others in 
the English language, but that this last edi- 
tion is superior to its predecessors. It is 
evident that the author has devoted a con- 
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preparation, nearly every page bearing evi- 
dences of careful revision. Although the 
work of the American editor in former 



adopted in a modified form in this revision, 
much was still left to be done by the editor 
to render the work iully adapted to the 
wants of our American students, so that the 
American edition will undoubtedly continue 
to supply the market on this side of the 
Atlantic. The work has been published in the 
characteristic creditable style of the Lea's, 
and owing to its enormous sale is offered at 
an extremely low price. — The Medical and 
Surgical Reporter, January 9, 1892. 



Chapman's Physiology. 

A Treatise on Human Physiology. By Henry C. 
Chapman, M. D., Professor of Institutes of Medicine and Medical Juris- 
prudence in the Jefferson Medical College of Philadelphia. In one hand- 
some octavo volume of 925 pages, with 605 fine engravings. Cloth, $5.50 ; 
leather, $6.50. 

Dalton's Physiology— Seventh Edition. 

A Treatise on Human Physiology. Desigued for the 
use of Students and Practitioners of Medicine. By John C. Dalton, 
M. D., Professor of Physiology in the College of Physicians and Surgeons, 
New York, etc. Seventh edition, thoroughly revised and rewritten. In 
one very handsome octavo volume of 722 pages, with 252 beautiful engrav- 
ings on wood. Cloth, $5.00 ; leather, $6.00. 

From the first appearance of the book it 
has been a favorite, owing as well to the 
author's renown as an oral teacher as to the 
charm of simplicity with which, as a writer, 
he always succeeds in investing even intri- 
cate subjects. It must be gratifying to him 
to observe the frequency with which his 
work, written for students and practitioners, 



is quoted by other writers on physiology. 
This fact attests its value, and, in great 
measure, its originality. It now needs no 
such seal of approbation however, for the 
thousands who have studied it in its various 
editions have never been in any doubt as to 
its sterling worth. — Ntw York Medical Jour- 
nal, October, 1882. 



Physics, Chemistry. 
Draper's Medical Physics. 

Medical Physics. A Text-book for Students and Practi- 
tioners of Medicine. By John C. Draper, M. D., LL. D., Professor of 
Chemistry in the University of the City of New York. In one octavo vol- 
ume of 734 pages, with 376 woodcuts, mostly original. Cloth, $4.00. 



Simon's Chemistry— Third Edition. 

Manual of Chemistry. A Guide to Lectures and Labora- 
tory work for Beginners in Chemistry. A Text-book, specially adapted 
for Students of Pharmacy and Medicine. By W. Simon, Ph. D., M. D., 
Professor of Chemistry and Toxicology in the College of Physicians and 
Surgeons, Baltimore, and Professor of Chemistry in the Maryland College 
of Pharmacy. New (third) edition. In one 8vo. volume of 477 pages, 
with 44 woodcuts and 7 colored plates illustrating 56 of the most impor- 
tant chemical tests. Cloth, $3.25. 



Among the many works on chemistry 
offered for the use of the medical student, 
there is prohably none that outrivals Dr. 
Simon's work in practical arrangement and 
thoroughness. A special feature of the 
book, and one that deserves the greatest 
praise, is the presence therein of the beauti- 
ful colored plates representing fifty-six 
chemical reactions. To say that they are 
splendidly and artistically executed hardly 



does them justice. They must convey to 
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of the color changes that he has noted in his 
experiments in the laboratory, and the 
perusal of this work must recall them 
vividly to recognition. The many cuts are 
well selected, and the make-up of the book 
leaves nothing to be desired. As a student's 
manual this work is of the highest order. — 
The Medical News, February 20, 1892. 



Fownes' Chemistry— Twelfth Edition. 

A Manual of Elementary Chemistry ; Theoretical and 
Practical. Embodying Watts' Physical and Inorganic Chemistry. By 
George Fownes, Ph. D. New American, from the twelfth English edi- 
tion. In one large royal 12mo. volume of 1061 pages, with 168 illustra- 
tions on wood and a colored plate. Cloth, $2.75 ; leather, $3.25. 



Attfield's Chemistry— Twelfth Edition. 

Chemistry, General, Medical and Pharmaceutical; 
Including ^he Chemistry of the XJ. S. Pharmacopoeia. A Manual of the 
General Principles of the Science, and their Application to Medicine and 
Pharmacy. By John Attfield, M.A., Ph.D., P.I.C., F.R.S., Etc., 
Professor of Practical Chemistry to the Pharmaceutical Society of Great 
Britain, etc. A new American, from the twelfth English edition, .specially 
revised by the Author for America. In one handsome royal 12mo. vol- 
ume of 782 pages, with 88 illustrations. Cloth, $2.75 ; leather, $3.25. 



Chem., Pharm., Therap., Hat. Hed. 
Bloxam's Chemistry— Fifth Edition. 

Chemistry, Inorganic and Organic. By Charles L. 
Bloxam, Prof, of Chemistry in King's College, London. New American 
from the fifth London edition, thoroughly revised and much improved. In 
one very handsome octavo vol. of 727 pages, with 292 illus. Cloth, $2.00 ; 
leather, $3.00. 

Remsen's Theoretical Chemistry— New (4th) Ed. 

Principles of Theoretical Chemistry, with special ref- 
erence to the Constitution of Chemical Compounds. By Iea Remsen, 
M. D., Ph. D., Professor of Chemistry in the Johns Hopkins University, 
Baltimore. Fourth and thoroughly revised edition. In one handsome 
royal 12mo. volume of 325 pages. Cloth, $2.00. Just ready. 



Parrish's Pharmacy— Fifth Edition. 



A Treatise on Pharmacy : Designed as a Text-book for 
the Student, and as a Guide for the Physician and Pharmaceutist. With 
many Formulae and Prescriptions. By Edward Parrish, late Professor 
of the Theory and Practice of Pharmacy in the Philadelphia College of 
Pharmacy. Fifth edition, thoroughly revised, by Thomas S. Wiegand, 
Ph. G. In one handsome octavo volume of 1093 pages, with 256 illustra- 
tions. Cloth, $5.00 ; leather, $6.00. 



Stille & Maisch's National Dispensatory— 4th Ed. 

The National Dispensatory. Containing the Natural 
History, Chemistry, Pharmacy, Actions and Uses of Medicines, including 
those recognized in the Pharmacopoeias of the United States, Great Britain 
and Germany, with numerous references to the French Codex. By 
Alfred Stille, M. D ., LL. D., Professor Emeritus of the Theory and 
Practice of medicine and of Clinical Medicine in the University of Penn- 
sylvania, and John M. Maisch, Phar. D., Professor of Materia Medica 
and Botany in Philadelphia College of Pharmacy, Secretary to the Amer- 
ican Pharmaceutical Association. Fourth edition revised, and covering 
the new British Pharmacopoeia. In one magnificent imperial octavo vol- 
ume of 1794 pages, with 311 elaborate engravings. Price in cloth, $7.25 ; 
leather, raised bands, $8.00; half Russia, $9.00. \* This work will be 
furnished with Patent Beady Reference Thumb-letter Index for $1.00 in addi- 
tion to the price in any of the above styles of binding. » 

neither the physician nor the pharmacist 
can do without the latest text-hooks on 
them, especially those that are so accurate 



We thinB. it a matter for congratulation 
that the profession of medicine and that of 
pharmacy have shown such appreciation 
of this great work as to call for four editions 
w 7 ithin trie comparatively brief period of 
eight years. The matters with which it- 
deals are of so practical a nature that 



and comprehensive as this one. The book 
is in every way creditable both to the au- 
thors and to the publishers. — New York Med- 
ical Journal, May 21, 1887. 



Therapeutics, flateria fledica, 



Hare's Practical Therapeutics— Second Edition. 

A Text-Book of Practical Therapeutics; With 
Especial Reference to the Application of Remedial Measures to Disease 
and their Employment upon a Rational Basis. By Hobakt Amory 
Hare, B. Sc., M. D v Professor of Materia Medica and Therapeutics in 
the Jefferson Medical* College of Philadelphia ; Secretary of the Conven- 
tion for the Revision of the United States Pharmacopoeia of 1890. With 
special chapters by Drs. G. E. de Schweinitz, Edward Martin, J. 
Howard Reeves and Barton C. Hirst. New (2d) and revised edition. 
In one handsome octavo vol. of 650 pages. Cloth, $3.75 ; leather, $4.75. 



This work has received the rare distinc- 
tion among medical works of reaching a 
second edition six months after its first ap- 
pearance. Many new prescriptions have 
also been inserted to illustrate the best 
modes of applying remedies. Among other 
features of this practically helpful treatise 
which will make reference to it convenient 
and profitable, are the arrangement of titles 



of drugs and diseases in alphabetical order, 
according to their English names; and a 
dose list of drugs officinal and unofficinal. 
In addition to the general index, a copious 
and explanatory index of diseases and rem- 
edies has been appended which will render 
the contents easily accessible. — The Medical 
Age, July 10, 1891. 



fflaisch's Materia Medica— New (5th) Ed. Just Ready. 

A Manual of Organic Materia Medica ; Being a Guide 
to Materia Medica of the Vegetable and Animal Kingdoms. For the nse 
of Students, Druggists, Pharmacists and Physicians. By John M. 
Maisch, Phar. D., Professor of Materia Medica and Botany in the Phil- 
adelphia College or Pharmacy. New (fifth) edition, thoroughly revised. 
In one very handsome 12mo. volume of 544 pages, with 270 engravings. 
Cloth, $3.00. 



Brunton's Therapeutics and Mat. Med.— 3d Ed. 

A Text-Book of Pharmacology, Therapeutics and 
Materia Medica ; Including the Pharmacy, the Physiological Action 
and Therapeutical Uses of Drugs. By T. Lauder Brunton, M. D., 
D. Sc, F. R. S., F. R. C. P., Lecturer on Materia Medica and Therapeutics 
at St. Bartholomew's Hospital, London, etc. Adapted to the U. S. Phar- 
macopoeia by Francis H. Williams, M. D., of Harvard University 
Medical School. Third edition. Octavo, 1305 pages, 230 illustrations. 
Cloth, $5.50 ; leather, $6.50. 



Edes' Therapeutics and Materia Medica. 

A Text-Book of Therapeutics and Materia Medica. 
Intended for the Use of Students and Practitioners. By Robert T. 
Edes, M. D., Jackson Professor of Clinical Medicine in Harvard University, 
Medical Department. Octavo, 544 pages. Cloth, $3.50; leather, $4.50. 



Practice of fledicine. 



Lyman's Practice— Just Ready. 

The Principles and Practice of Medicine. For the 
Use of Medical Students and Practitioners. By Henry M. Lyman, M. D., 
Professor of the Principles and Practice of Medicine, Rush Medical Col- 
lege, Chicago. In one very handsome octavo volume of 925 pages, with 
170 illustrations. Cloth, $4.75; sheep, $5.75. 

The author has undertaken to present in this volume not only the 
results of his long experience as a practitioner and teacher, but to make it 
representative of the latest state of knowledge in its department. The 
work is assured of wide use as an unsurpassed guide for the student and 
likewise for the rjractitioner. 

Flint's Practice— Sixth Edition. 

A Treatise on the Principles and Practice of Med- 
icine. Designed for the use of Students and Practitioners of Medicine. 
By Austin Flint, M. D., LL. D., Professor of the Principles and Prac- 
tice of Medicine and of Clinical Medicine in Bellevue Hospital Medical 
College, New York. Sixth edition, thoroughly revised and rewritten 
by the Author, assisted by William EL Welch, M. D., Professor 
of Pathology, Johns Hopkins University, Baltimore, and Austin Flint, 
Je., M. D., LL. D., Professor of Physiology, Bellevue Hospital Medical 
College, New York. In one very handsome octavo volume of 1160 pages, 
with illustrations. Cloth, $5.50; leather, $6.50. 



No text-book on the principles and prac- 
tice of medicine has ever met in this country 
with such general approval by medical stu- 
dents and practitioners as the work of Pro- 
fessor Flint. In all the medical colleges of 
the United States it is the favorite work 
upon Practice; and, as we have stated be- 
fore in alluding to it, there is no other medi- 
cal work that can be so generally found in 
the libraries of physicians. In every state 
and territory of this vast country the book 
that will be most likely to be found in the 
office of a medical man, whether in city, 



town, village, or at some cross-roads, is 
Flint's Practice. We make this statement to 
a considerable extent from personal observa- 
tion, and it is the testimony also of others. 
An examination shows that very considera- 
ble changes have been made in the sixth 
edition. The work may undoubtedly be re- 
garded as fairly representing the present 
state of the science of medicine, and as 
reflecting the views of those who exemplify 
in their practice the present stage of pro- 
gress of medical art. — Cincinnati Medical 
News, Oct. 18S6. 



Hartshorne's Essentials— Fifth Edition. 

Essentials of the Principles and Practice of Medi- 
cine. A Handbook for Students and Practitioners. By Henry Harts- 
horns, M. D., LL. D., lately Professor of Hygiene in the University of 
Pennsylvania. Fifth edition, thoroughly revised and rewritten. In one 
royal 12mo. volume of 669 pages, with 144 illustrations. Cloth, $2.75; 
half bound, $3.00. 

An indispensable book. No work ever 
exhibited a better average of actual practical 
treatment than this one; and probably not 
one writer in our day had a better opportu- 
nity than Dr. Hartshorne for condensing all 
the views of eminent practitioners into a 
12mo. The numerous illustrations will be 



very useful to students especially. These 
essentials are most valuable in affording the 
means to see at a glance the whole literature 
of any disease, and the most valuable treat- 
ment. — Chicago Medical Journal and Ex- 
aminer, April, 1882. 



Practice of fledicine, Histology, Pathology. 
Whitla's Dictionary of Treatment. 

A Dictionary of Treatment; op Therapeutic Index, 
including Medical and Surgical Therapeutics. By William 
Whitla, M. D., Professor of Materia Medica and Therapeutics iu the 
Queen's College, Belfast. Eevised and adapted to the United States Phar- 
macopoeia. In one square, octavo volume of 917 pages. Cloth, $4.00. 

Fothergill's Handbook of Treatment— 3d Edition. 

The Practitioner's Handbook of Treatment; Or, the 
Principles of Therapeutics. By J. M Fothekgill, M.D., Edin, M.K.C.P., 
Lond., Physician to the City of London Hospital for Diseases of the Chest. 
Third edition. In one 8vo. vol. of 661 pages. Cloth, $3.75 ; leather, $4.75. 



Flint's Auscultation and Percussion— Fifth Edition. 

A Manual of Auscultation and Percussion ; Of the 
Physical Diagnosis of Diseases of the Lungs and Heart, and of Thoracic 
Aneurism. By Austin Flint, M. D., LL. D., Professor of the Principles 
and Practice of Medicine in Belle vue Hospital Medical College, N. Y. Fifth 
edition. Edited by James C. Wilson, M. D., Lecturer on Physical Diag- 
nosis in the Jefferson Medical College, Philadelphia. In one handsome 
royal 12mo. volame of 274 pages, with 12 illustrations. Cloth, $1.75. 



Gibbes' Pathology and Histology. 

Practical Pathology and Morbid Histology. By 
Heneage Gibbes, M. D., Professor of Pathology in the University of 
Michigan, Medical Department. In one very handsome octavo volume of 
314 pages, with 60 illustrations, mostly photographic. Cloth, $2.75. 



This is, in part, an expansion of the little 
work published by the author some years 
ago, and his acknowledged skill as a practi- 
cal microscopist will give weight to his in- 
structions. Indeed, in fulness of directions 
as to the modes of investigating morbid tis- 



sues the book leaves little to be desired. The 
work is throughout profusely illustrated 
with reproductions of micro-photographs. 
We may say that the practical histologist 
will gain much useful information from the 
book.— The London Lancet, January 23, 1892. 



Green's Pathology and Morbid Anatomy—7tli Ed. 

Pathology and Morbid Anatomy. By T. Henry Green, 
M. D., Lecturer on Pathology and Morbid Anatomy at Charing-Cross Hos- 
pital Medical School, London. Sixth American from the seventh revised 
English edition. Octavo, 539 pages, with 167 engravings. Cloth, $2.75. 



It is better adapted to the wants of gen- 
eral practitioners than any work of the kind 
with which we are acquainted. The cuts 
exhibit the appearances of pathological 
Btructures just as they are seen through the 



microscope. The fact that it is so generally 
employed as a text-book by medical students 
is evidence that we have not spoken too much 
in its favor.— Cincinnati Medical News, Octo- 
ber, 1889. 



Pathology, Histology, Bacteriology. 
Payne's General Pathology. 

A Manual of General Pathology. Designed as an Intro- 
duction to the Practice of Medicine. By Joseph F. Payne, M. D., 
F. R. C. P., Senior Assistant Physician and Lecturer on Pathological 
Anatomy, St. Thomas' Hospital, London. Octavo of 524 pages, with 152 
illustrations and a colored plate. Cloth, $3.50. 

in those diseases now with reasonable cer- 



Knowing, as a teacher and examiner, the 
exact needs of medical students, the author 
has in the work before us prepared for their 
especial use what we do not hesitate to say 
is the best introduction to general pathology 
that we have yet examined. A departure 
which our author has taken is the greater 
attention paid to the causation of disease, 
and more especially to the etiological factors 



tainty ascribed to pathogenetic microbes. 
In this department he has been very full 
and explicit, not only in a descriptive man- 
ner, but in the technique of investigation. 
The Appendix, giving methods of research, 
is alone worth the price of the book, several 
times over, to every student of pathology. — 
Ht. Louis Med. and Surgical Jour., Jan. 1889. 



Klein's Histology— Fourth Edition. 

Elements of Histology. By E. Klein, M. D., F. R. S., 
Joint Lecturer on General Anatomy and Physiology in the Medical School 
of St. Bartholomew's Hospital, London. Fourth edition. In one 12mo. 
volume of 376 pages, with 194 illustrations. Limp cloth, $1.75. 



Abbott's Bacteriology. 

The Principles of Bacteriology : a Practical Manual for 
Students and Physicians. By A. C. Abbott, M. D., First Assistant, Lab- 
oratory of Hygiene, Univeisity of Pennsylvania, Philadelphia. In one 
12mo. volume of 259 pages, with 32 illustrations. Cloth, $2.00. Just ready. 

On reading this manual of Dr. Abbott, any 
one familiar with the subject will readily 
recognize the fact that the book is not 
merely a compilation from other works, but 
one giving evidence of the originality of the 



author, as well as complete knowledge of 
the practical details of bacteriology. His 
"scheme for the study of an organism" 



furnishes an excellent guide to the student. 
Of equal importance is the chapter on disin- 
fectants, antiseptics and skin disinfection. 
It will form a valuable addition to the litera- 
ture of laboratory technique and bacterio- 
logical investigation,— The Therapeutic Ga- 
zette, May 16, 1892. 



Senn's Surgical Bacteriology— Second Edition. 

Surgical Bacteriology. By Nicholas Sexn, M. D., 
Ph. D., Professor of Surgery in Rush Medical College, Chicago. New 
(second) edition. In one handsome octavo of 268 pages, with 13 plates, of 
which 10 are colored, and 9 engravings. Cloth, $2.00. 



Coats' Pathology. 



A Treatise on Pathology. By Joseph Coats, M. D., 
F. F. P. S., Pathologist to the Glasgow Western Infirmary. In one very 
handsome octavo volume of 829 pages, with 339 beautiful illustrations. 
Cloth, $5.50 ; leather, $6.50. 



Nervous and flental Diseases, Surgery. 
Gray on Nervous and Mental Diseases. 

A Practical Treatise on Nervous and Mental Dis- 
eases. By Landon Cakter Gray, M. D.. Professor of Diseases of the 
Mind and Nervous System in the New York Polyclinic. Shortly. 
nPHIS work is devoted purely to the practical aspects of nervous and mental 
- 1 - diseases, especial care being taken to present the fundamental knowledge 
essential to a grasp of its subjects and to cast everything in the clearest possible 
form. The series of illustrations is rich and unique, embracing a large num- 
ber of photographic engravings of exceptional vividness and interest. By the 
employment of a style at once concise and clear, and by careful arrangement, 
the author is enabled to include an exposition of a vast and important subject 
in a condensed and convenient form. It will be an admirable work for the 
student as well as for the practitioner. 



Ross on Nervous Diseases. 

A Handbook on Diseases of the Nervous System. 
By James Eoss, M. D., F. R. C. P., LL. D., Senior Assistant Physician to 
the Manchester Royal Infirmary. In one octavo volume of 725 pages, with 
184 illustrations. Cloth, $4.50 ; leather, §5.50. 



This admirable work is intended for 
students of medicine and for such medical 
men as bave no time for lengthy treatises. 
In every part this handbook merits the 



highest praise, and will no doubt be found 
of the greatest value to the student as well 
as to the practitioner.— Edinburgh Medical 
Journal, Jan. 1887. 



Roberts' Modern Surgery. 



The Principles and Practice of Modern Surgery. 

For the nse of Students and Practitioners of Medicine and Surgery. By 
John B. Roberts, M. D., Professor of Anatomy and Surgery in the Phila- 
delphia Polyclinic ; Professor of the Principles and Practice of Surgery in 
the Woman's Medical College of Pennsylvania; Lecturer in Anatomy in 
the University of Pennsylvania. In one very handsome octavo volume of 
780 pages, with 501 illustrations. Cloth, $4.50 ; leather, $5.50. 

vanced doctrines and methods of practice of 
the present day. Its general arrangement 
follows this rule, and the author in his desire 



This work is a very comprehensive man- 
ual upon general surgery, and will doubtless 
meet with a favorable reception by the pro- 
fession. It has a thoroughly practical charac- 
ter, the subjects are treated with rare judg- 
ment, its conclusions are in accord with 
those of the leading practitioners of the art, 
and its literature is fully up to all the ad- 



to be concise and practical is at times almost 
dogmatic, but this is entirely excusable con- 
sidering the admirable manner in which he 
has thus increased the usefulness of his 
work.— Medical Record, Jan. 17, 1891. 



Erichsen's Surgery— Eighth Edition. 

The Science and Art of Surgery; Being a Treatise on 
Surgical Injuries, Diseases and Operations. By John E. Erichsen, F.R.S., 
F. R. C. S., Professor of Surgery in University College, London, etc. From 
the eighth and enlarged English edition. In two large 8vo. volumes of 2316 
pages, with 984 engravings on wood. Cloth, $9.00 ; leather, $11.00. 



Surgery. 
Ashhurst's Surgery— Fifth Edition. 

The Principles and Practice of Surgery. By Jonx 
Ashhurst, Jr., M. D., Barton Professor of Surgery and Clinical Surgery 
in the University of Pemra; Surgeon to the Penn'a Hospital, Phila. Fifth 
edition, enlarged and thoroughly revised. In one large and handsome 
octavo volume of 1144 pages, with 642 illas. Cloth, $6.00 ; leather, $7.00. 

A complete and most excellent work on 
surgery. It is only necessary to examine it 
to see at once its excellence and real merit 



either as text-book lor the student or a 
guide for the general practitioner. It fully 
considers in detail every surgical injury 
and disease to which the body is liable, and 



every advance in surgery worth noting is 
to be found in its proper place. It is un- 
questionably the best and most complete 
single volume on surgery, in the English 
language, and cannot but" receive that con- 
tinued appreciation which its merits justly 
demand.— Southern Practitioner. Feb. 1890. 



Druitt's Modern Surgery. 

Manual of Modern Surgery. By Robert Druitt, 
M. R. C. S., etc. Twelfth edition, thoroughly revised by Stanley Boyd, 
M. B., B. S., F. R. C. S. In one 8vo. volume of 965 pages, with 373 illus- 
trations. Cloth, $4.00 ; leather, $5.00. 

Bryant's Surgery— Fourth Edition. 

The Practice of Surgery. By Thomas Bryant, F.R.C.S , 
Surgeon and Lecturer on Surgery at Guy's Hospital, London. Fourth 
American from the fourth and revised English edition. In one large and 
very handsome imperial octavo volume of 1040 pages, with 727 illustra- 
tions. Cloth, $6.50 ; leather, $7.50. 

Wharton's Minor Surgery and Bandaging. 

Minor Surgery and Bandaging. By Henry R. Whar- 
ton, M.D., Demonstrator of Surgery and Lecturer on Surgical Diseases of 
Children in the University of Penna. In one very handsome 12mo. volume 
of 498 pp., with 403 engravings, many being photographic. Cloth, $3.00. 

This new work must take a first rank as 
soon as examined. Bandaging is well de- 
scribed by words, and the methods are illus- 
trated by photographic drawing?, so to make 
plain each step taken in the application of 
bandages of various kinds to different parts 
of the body and extremities— including the 
head. The various operations are likewise 
described and illustrated, so that it would 
seem easy for the tyro to do the gravest 
amputation. The various established opera- 



tions are described in detail. Hence this 
work becomes a most valuable companion- 
book to any of the more pretentious treatises 
on surgery, where simply the general advice 
is given to bandage, amputate intubate, 
operate, etc. For the student and young 
surgeon, it is a very valuable instruction 
book from which to learn how to do what 
may be advised, in general terms, to be done. 
— Virginia Medical Monthly, October, 1891. 



Holmes' Treatise on Surgery. 

A Treatise on Surgery ; Its Principles and Practice. 

By Timothy Holmes, M.A., Surgeon and Lecturer on Surgery at St. 
George's Hospital, London. From the fifth English edition, edited by T. 
Pickering Pick, F. R. C. S. In one octavo volume of 997 pages, with 428 
illustrations. Cloth, $6.00; leather, $7.00. 



Surgery. 



Treves 1 Operative Surgery. 



A Manual of Operative Surgery. By Fredetitck 
Treves, F. R. C. S., Surgeon and Lecturer on Anatomy at the London 
Hospital. In two octavo volumes containing 1550 pages, with 422 oiiginal 
engravings. Complete work, cloth, $9.00 ; leather, §11.00. 



We have no hesitation in declaring it the 
best work on the subject in the English 
language, and indeed in many respects 
the best in any language. We feel called 
upon to recommend the book so strongly for 
the excellent judgment displayed in the 
arduous task of selecting from among the 
thousands of varying procedures those most 



worthy of description ; for the way in which 
the still more difficult task of choosing among 
the best of those hasbeen accomplished ; and 
for the simple, clear, straightforward manner 
in which the information thus gathered 
from all surgical literature has been con- 
veyed to the reader.— Annals of Surgery. 
March, 1892. 



Smith's Operative Surgery. 

The Principles and Practice of Operative Surgery. 
By Stephen Smtth, M. D., Professor of Clinical Surgery in the University 
of the City of New York. Second and thoroughly revised edition. In one 
very handsome octavo volume of 892 pages, with 1005 illustrations. Cloth, 
$4.00; leather, $5.00. 



It can be truly said that as a handbook 
for the student, a companion for the sur- 
geon, and even as a book of reference for the 
physician not especially engaged in the 

Eractice of surgery, this volume will long 
old a most conspicuous place, and seldom 



will its readers, no matter how unusual the 
subject, consult its pages in vain Its com- 
pact form, excellent print, numerous illustra- 
tions, and especially its decidedly practical 
character, all combine to commend it. — .Bos- 
ton. Medical and Surgical Journal, May 10, '88. 



Hamilton on Fractures and Dislocations. 

A Practical Treatise on Fractures and Dislocations. 
By Feank H. Hamilton, M. D., LL. D., Surgeon to Bellevue Hospital, 
New York. New (eighth) edition, revised and edited by Stephen Smith, 
A. M., M. D., Professor of Clinical Surgery in the University of the City of 
New York. In one very handsome octavo volume of 832 pages, with 507 
illustrations. Cloth, $5.50; leather, $6.50. 

The more one reads the more one is im- 
pressed with its completeness. The work 
has been accomplished, and has been done 



It is pre-eminently the authority on frac- 
tures and dislocations, and universally 
quoted as such. The additions it has re- 
ceived by its recent revision make it a work 
thoroughly in accordance with modern prac- 
tice, theoretically, mechanically, aseptically. 



clearly, concisely, excellently well.— Boston 
Medical and Surgical Journal, May 26, 1892. 



Stimson's Operative Surgery. 



A Manual of Operative Surgery. By Lewis A. Stimson, 
B. A., M. D., Professor of Clinical Surgery in the Medical Faculty of the 
University of the City of New York. Second edition. In one very hand- 
some royal 12mo. volume of 503 pages, with 342 illustrations. Cloth, $2 50. 



Surgery, Ophthalmology, Otology. 
Stimson on Fractures and Dislocations. 

A Treatise on Fractures and Dislocations. In two 
handsome octavo volumes. Vol. I., Fractures, 582 pages, 360 beautiful 
illustrations. Vol. II., Dislocations, 540 pages, with 163 illustrations. 
Complete work, cloth, $5.50; leather, $7.50. Either volume separately, 
cloth, $3.00 ; leather, $4.00. 
The appearance of the second volume ( and Dislocations. The volume on Fractures 



marks the completion of the author's origi 
nal plan of preparing a work which should 
present in the fullest manner all that is 
known on the cognate subjects of Fractures 



assumed at once the position of authority on 
the subject, and its companion on Disloca- 
tions will no doubt be similarly received.— 
Cincinnati Medical News, May, 1888. 



Norris & Oliver on the Eye— In Press. 

A Text-Book of Ophthalmology. By William F. 
Norris, M. D., Clinical Professor of Ophthalmology in University of 
Penna., and Charles A. Oliver, M.D. In one octavo volume of about 
800 pages, richly illustrated with engravings and colored plates. In press. 
TN PRE PAKING this volume the authors have had in view the needs of 
-L students, physicians and specialists. Its concise and clear style, its 
completeness and the beautiful series of illustrations will at once render it a 
favorite work with all classes for whom it is intended. 



Nettleship's Students' Guide tc the Eye— 5th Ed. 

Diseases of the Eye. By Edward Nettleship, F.R.C.S., 
Ophthalmic Surgeon at St. Thomas' Hospital, London. Surgeon to the 
Royal London (Moorfields) Ophthalmic Hospital. Fourth American from 
the fifth English edition, thoroughly revised. With a Supplement on the 
Detection of Color Blindness, by William Thomson, M. D., Professor of 
Ophthalmology in the Jefferson Medical College. In one 12mo. volume 
of 500 pages, with 164 illustrations, selections from Snellen's test-types 
and formulae, and a colored plate. Cloth, $2.00 
It was primarily intended for the use of 



students, and supplies their needs adinir 
ably, but it is as useful for the practitioner. 
It does not presuppose the large amount of 
recondite knowledge to be present which 



seems to be assumed in some of our larger 
works, is not tedious from over-conciseness, 
and yet covers the more important parts of 
clinical ophthalmology. — New York Medical 
Journal, December 13, 1S90. 



Burnett on the Ear. 

The Ear ; Its Anatomy, Physiology and Diseases. A 
Practical Treatise for the use of Medical Students and Practitioners. By 
Charles H. Burnett, A.M., M.D., Professor of Otology in the Philadel- 
phia Polyclinic ; President of the American Otological Society. Second 
edition. In one handsome octavo volume of 580 pages, with 107 illustra- 
tions Cloth, $4.00 ; leather, $5.00. 



Dr. Burnett has fully maintained his rep- 
utation, for the book is replete with valuable 
information and suggestions. The revision 
has been carefully carried out, and much 
new matter added. Dr. Burnett's work 
must be regarded as a very valuable contri- 



bution to aural surgery, not only on account 
of its comprehensiveness, but because it con- 
tains the results of the careful personal 
observation and experience of this eminent 
aural surgeon. — London Lancet, Feb. 21, 1885. 



Urinary, Venereal, Skin. 
Roberts on Urinary Diseases— Fourth Edition. 

A Practical Treatise on Urinary and Eenal Diseases, 
including Urinary Deposits. By Sir William Eobeets, M. D., 
Lecturer on Medicine in the Manchester School of Medicine, etc. Fourth 
American from the fourth London edition. In one handsome octavo 
of 609 pages, with 81 illustrations. Cloth, §3.50. 



Jackson on the Skin— Just Ready. 

The Ready-Reference Handbook of Skin Diseases. 
By George Thomas Jackson, M. D., Professor of Dermatology, Women's 
Medical College, New York Infirmary. In one 12mo. volume of 450 pages- 
with 50 illustrations. Cloth, $2.75. 

This volume is devoted to the art of dermatology, to the practice of this 
department of medicine in its latest development. No attempt has been 
made to discuss debatable questions, and pathology and etiology do not 
receive as full consideration as symptomatology, diagnosis and treatment. 
The alphabetical arrangement of the different diseases has been adopted a& 
conducive to the greatest possible convenience in use. The pages are 
illustrated with a large number of engravings, many being photographic 
and vivid reproductions of actual cases. A handsome lithographic frontis- 
piece adds to the beauty and usefulness of a volume for which a wide recog- 
nition is assured. 

Culver & Hayden on Venereal Diseases. 

A Manual of Venereal Diseases. By E M. Culver, 
M. D., Pathologist and Assistant Attending Surgeon, Manhattan Hospital, 
New York, and J. R. Hayden, M. D., Chief of Clinic Venereal Depart- 
ment, Vanderbilt Clinic, College of Physicians and Surgeons, New York. 
In one 12mo. volume of 289 pages, with 33 illustrations. Cloth, $1.75. 



Hyde on the Skin— Second Edition. 

A Practical Treatise on Diseases of the Skin. For 
the use of Students and Practitioners. By J. Nevins Hyde, A.M., M.D., 
Prof, of Dermatology and Venereal Diseases in Push Med. College, Chicago. 
Second edition. In one handsome octavo volume of 676 pages, 2 colored 
plates and 85 beautiful and elaborate illus. Cloth, $4.50; leather, $5.50. 
Histreatise is like his clinical instruction, I into his book all the best of that -which the 
admirably arranged, attractive in diction | past years have brought forth. The pre- 
and strikingly practical throughout. No I scriptions and formulae are given in both 



clearer description of the lesions of the skin 
is to be met with anywhere. Dr. Hyde has 
shown himself a comprehensive reader of 
the latest literature, and has incorporated 



common and metric systems. Text and 
illustrations are good, and colored plates of 
rare cases lend additional attractions. — Med~ 
ical Press of Western New York, June, 1888. 



Hardaway's Manual of Skin Diseases. 

Manual of Skin Diseases. With Special Reference to 
Diagnosis and Treatment. For the Use of Students and General Practi- 
tioners. By W. A. Haedaway, M. D., Professor of Skin Diseases in the 
Missouri Medical College, St. Louis. 12mo., 440 pages. Cloth, $3.00. 



Gynecology, 



Thomas & Munde on Women— Sixth Edition. 

A Practical Treatise on the Diseases of Women. 
By T. Gaillard Thomas, M. D., LL. D., Emeritus Professor of Diseases 
of Women in the College of Physicians and Surgeons, New York, and 
Paul F. Munde, M. D., Professor of Gynecology in the New York Poly- 
clinic. New (sixth) edition, thoroughly revised and rewritten by Dr 
Munde\ In one large handsome octavo volume of 824 pages, with 347 illus- 
trations, of which 201 are new. Cloth, $5.00; leather, $6.00. 

Probably no treatise ever written by an tion and scholarly and scientific statement 
American author on a medical topic has must remain what it long has been, a stand- 
been accepted by more practitioners, as a »rd text-book both for practitioner and stu- 
standard text-book, or read with pleasure dent, at home and abroad, and an enduring 
and profit by more medical students than pride to American gynecologists. — Tlie 
Thomas on the diseases of women. This Brooklyn Medical Journal, March, 1892. 
volume in classic excellence, elegance of die- 



Davenport's Non-Surgical Gynaecology— New Ed. 

Diseases of Women, a Manual of Won- Surgical 
Gynaecology. Designed especially for the Ute of Students and General 
Practitioners. By F. H. Davenport, M. D., Assistant in Gynaecology in 
the Medical Department of Harvard University, Boston. New (second) 
edition. In one handsome 12mo. volume of 314 pages, with 106 illustra- 
tions. Cloth, $1.75. Just ready. 



Comparatively few practitioners are pre- 
pared to perform the graver gynecological 
operations, hut all are compelled to deal with 
the multitudinous ailments of women, and in 
many instances non-surgical measures are 
preferable, though neglected by those whose 
special skill has enlarged the field of opera- 
tive interference. The present vol ume deals 



with nothing which has not stood the actual 
test of experience, and being concisely and 
clearly written it conveys a great amount 
of information in a convenient space. The 
demand for two editions in less than three 
years confirms its usefulness. — The Medical 
Brief, August, 1892. 



May on Diseases of Women— Second Edition. 

A Manual of the Diseases of Women. Being a concise 
and systematic exposition of the theory and practice of Gynecology. By 
Charles H. May, M. D., late House Surgeon to Mount Sinai Hospital, 
New York. Second edition, edited by L. S. Ran, M.D., Attending Gynecol- 

In one 12mo. volume of 360 pages, 



ogist at the Harlem Hospital, N. Y. 
Tvith 31 illustrations. Cloth, $1.75. 
This is a manual of gynecology in a very 
condensed form, and the fact that a second 
edition has been called for indicates that it 
has met with a favorable reception. It is 
intended, the author tells us, to aid the stu- 
dent who after having carefully perused lar- 



ger works desires to review the subject, and 
he adds that it may be useful to the prac- 
titioner who wishes to refresh his memory 
rapidly but has not the time to consult lar- 
ger woiks. — The Physician and Surgeon, 
June, 1890. 



Obstetrics, 



Parvin's Obstetrics— Second Edition. 

The Science and Art of Obstetrics. By Thkophilus 
Paryin, M. D., LL. D., Professor of Obstetrics and the Diseases of Women 
and Children in Jefferson Medical College, Philadelphia. Second edition. 
In one handsome 8vo. volume of 701 pages, with 239 engravings and a 
colored plate. Cloth, $4.25 ; leather, $5.25. 



The second edition of this work is fully 
up to the present state of advancement of 
the obstetric art. Rarely in the range of ob- 
stetric literature can be found a work which 
is so comprehensive and yet compact and 
practical. In such respect it is essentially a 



text-book of the first merit. The treatment 
of the subject gives a real value to the work 
—the individualities of a practical teacher, 
a skilful obstetrician, a close thinker and a 
ripe scholar.— Medical Record, Jan. 17, 1891. 



Playfair's Midwifery— Seventh Edition. 

A Treatise on the Science and Practice of Mid- 
wifery. By W. S. Playfair, M. D., F. R. C. P., Professor of Obstetric 
Medicine in King's College, London, etc. Fifth American, from the 
seventh English edition. Edited, with additions, by Robert P. Harris, 
M. D. In one handsome octavo volume of 664 pages, with 207 engravings 
and 5 plates. Cloth, $4.00 ; leather, $5.00. 



Truly a wonderful book; an epitome of all 
obstetrical knowledge, full, clear and con- 
cise. In thirteen years it has reached seven 
editions. It is perhaps the most popular 
work of its kind ever presented to the pro- 
fession. Beginning with the anatomy and 
physiology of the organs concerned, nothing 
is left un written that the practical accoucheur 
should know. It seems that every conceiv- 
able physiological or pathological condition 



from the moment of conception to the time 
of complete involution has had the author's 
patient attention. The plates and illustra- 
tions, carefully studied, will teach the sci- 
ence of midwifery. The reader of this book 
will have before him the very latest and best 
of obstetric practice, and also of all the 
coincident troubles connected therewith. — 
Southern Practitioner, December, 1889. 



King's Obstetrics— New Edition. Just Ready. 

A Manual of Obstetrics. By A. F. A. Eing, M. D., Pro- 
fessor of Obstetrics and Diseases of Women in the Medical Department of 
the Columbian University, Washington, D. C, and in the University of 
Vermont, etc. New (Fifth) edition. In one 12mo. volume of 450 pages, 
with 150 illustrations. Cloth, $2.50. 



So comprehensive a treatL.. could not be 
brought within the limits of a book of this 
size, were not two things especially true. 
First, Dr. King is a teacher of many years' 
experience, and knows just how to present 
his subjects in a manner for them to be best 
received; and, secondly, he can put his ideas 
in a clear and concise form. In other words, 
he knows how to use the English language. 
He gives us the plain truth, free from un- 



necessary ornamentation. Therefore we say 
there are nine hundred pages of matter be- 
tween the covers of this manual of four 
hundred and fifty pages. We cannot imag- 
ine a better manual for the hard-worked 
student ; while its clean and practical teach- 
ings make it invaluable to the busy practi- 
tioner. The illustrations add much to the 
subject matter.— The National Medical Review, 
October, 1892. 



Dis. of Children, fled. Juris., Periodicals. 



Smith on Children— Seventh Edition. 

A Treatise on the Diseases of Infancy and Child- 
hood. By J. Lewis Smith, M. D., Clinical Professor of Diseases of 
Children in the Bellevue Hospital Medical College, N. Y. New (seventh) 
edition, thoroughly revised aud rewritten. In one handsome octavo vol- 
ume of 881 pages, with 51 illustrations. Cloth, $4.50; leather, $5.50. 



We have always considered Dr. Smith's 
book as one of the very best on the subject. 
It has always been practical — a field book, 
theoretical where theory has been deduced 
from practical experience. One seldom fails 
to find here a practical suggestion after 
search in other works has been in vain. In the 
seventh edition we note a variety of changes 



in accordance with the progress of th< times. 
It still stands foremost as the American text- 
book. The literary style could not be ex- 
celled, its advice is always conservative and 
thorough, and the evidence of research has 
long since placed its author in the front 
rank of medical teachers.— The American 
Journal of the Medical Sciences, Dec. 1891. 



Taylor's Medical Jurisprudence— New Edition. 

A Manual of Medical Jurisprudence. By Alfred S. 
Taylor, M. D., Lecturer on Medical Jurisprudence and Chemistry in 
Guy's Hospital, London. New American from the twelfth English edi- 
tion. Thoroughly revised by Clark Bell, Esq. , of the New York Bar. 
Octavo, 800 pages, 56 illus. Cloth, $4.50 ; leather, §5.50. Just ready. 



Subscription Price Reduced to $4.00 Per Annum. 

THE MEDICAL NEWS. 

The Medical News is alive to the wants of medical men in active 
practice and understands their adequate supply. The great circle of 
readers thus secured has rendered possible the reduction in the price of 
The News to Four Dollars per year, so that it is now by far the 
cheapest as well as the best large weekly journal published in America. 

In a word The Medical News is a crisp, fresh, weekly newspaper 
and as such occupies a well-marked sphere of usefulness, distinct and com- 
plementary to the ideal monthly magazine, The American Journal of 
the Medical Sciences. 



T§e American Journal of the fljedical jfoenceg, 

Published Monthly, at $4.00. Per Annum. 

Published continuously since 1820, The American Journal has been 
the medium chosen by the best minds of the profession during this period 
for the presentation of their ablest papers. It has therefore well earned 
the praise accorded it by an unquestioned authority — "from this file alone, 
were all other publications of the press for the last fifty years destroyed,, 
it would be possible to reproduce the great majority of the real contribu- 
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